diff --git a/app/Models/User.php b/app/Models/User.php
index e61df3ee..5235aac2 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -234,8 +234,8 @@ class User
     public function getAvatar($size)
     {
         // output image directly
-        if (!is_null($this->eloquent_model) && $this->eloquent_model->avatar) {
-            $png = \Minecraft::generateAvatarFromSkin(BASE_DIR."/textures/".Texture::find($this->eloquent_model->avatar)->hash, $size);
+        if (!is_null($this->eloquent_model) && $this->getAvatarId()) {
+            $png = \Minecraft::generateAvatarFromSkin(BASE_DIR."/textures/".Texture::find($this->getAvatarId())->hash, $size);
             header('Content-Type: image/png');
             imagepng($png);
             imagedestroy($png);
@@ -249,6 +249,11 @@ class User
         }
     }
 
+    public function getAvatarId()
+    {
+        return $this->eloquent_model->avatar;
+    }
+
     public function setAvatar($tid)
     {
         $this->eloquent_model->avatar = $tid;
diff --git a/app/Services/Utils.php b/app/Services/Utils.php
index 1f35e7b7..d805f0fa 100644
--- a/app/Services/Utils.php
+++ b/app/Services/Utils.php
@@ -52,4 +52,18 @@ class Utils
         return ($timestamp == 0) ? date('Y-m-d H:i:s') : date('Y-m-d H:i:s', $timestamp);
     }
 
+    public static function getNameOrEmail(\App\Models\User $user)
+    {
+        return ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName();
+    }
+
+    public static function getAvatarFname(\App\Models\User $user)
+    {
+        $fname = base64_encode($user->email).".png";
+        if (Option::get('avatar_query_string')) {
+            $fname .= '?v='.$user->getAvatarId();
+        }
+        return $fname;
+    }
+
 }
diff --git a/resources/views/admin/master.tpl b/resources/views/admin/master.tpl
index 8de44631..bdd4ce9c 100644
--- a/resources/views/admin/master.tpl
+++ b/resources/views/admin/master.tpl
@@ -50,12 +50,12 @@
                             <a href="#" class="dropdown-toggle" data-toggle="dropdown">
                                 <i class="fa fa-user"></i>
                                 <!-- hidden-xs hides the username on small devices so only the image appears. -->
-                                <span class="hidden-xs nickname">{{ ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName() }}</span>
+                                <span class="hidden-xs nickname">{{ Utils::getNameOrEmail($user) }}</span>
                             </a>
                             <ul class="dropdown-menu">
                                 <!-- The user image in the menu -->
                                 <li class="user-header">
-                                    <img src="../avatar/128/{{ base64_encode($_SESSION['email']) }}.png" alt="User Image">
+                                    <img src="../avatar/128/{{ Utils::getAvatarFname($user) }}" alt="User Image">
                                     <p>{{ $_SESSION['email'] }}</p>
                                 </li>
                                 <!-- Menu Footer-->
@@ -82,10 +82,10 @@
                 <!-- Sidebar user panel (optional) -->
                 <div class="user-panel">
                     <div class="pull-left image">
-                        <img src="../avatar/45/<?php echo base64_encode($_SESSION['email']); ?>.png" alt="User Image">
+                        <img src="../avatar/45/{{ Utils::getAvatarFname($user) }}" alt="User Image">
                     </div>
                     <div class="pull-left info">
-                        <p class="nickname">{{ ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName() }}</p>
+                        <p class="nickname">{{ Utils::getNameOrEmail($user) }}</p>
                         <i class="fa fa-circle text-success"></i> Online
                     </div>
                 </div>
diff --git a/resources/views/admin/options.tpl b/resources/views/admin/options.tpl
index 1215fc4b..de46d4ce 100644
--- a/resources/views/admin/options.tpl
+++ b/resources/views/admin/options.tpl
@@ -37,6 +37,7 @@
                                 // pre-set user_can_register because it will not be posted if not checked
                                 $_POST['user_can_register'] = isset($_POST['user_can_register']) ? $_POST['user_can_register'] : "0";
                                 $_POST['allow_chinese_playername'] = isset($_POST['allow_chinese_playername']) ? $_POST['allow_chinese_playername'] : "0";
+                                $_POST['avatar_query_string'] = isset($_POST['avatar_query_string']) ? $_POST['avatar_query_string'] : "0";
 
                                 foreach ($_POST as $key => $value) {
                                     // remove slash if site_url is ended with slash
@@ -106,6 +107,17 @@
                                         </td>
                                     </tr>
 
+                                    <tr>
+                                        <td class="key">头像缓存
+                                            <i class="fa fa-question-circle" title="如果对头像启用了 CDN 缓存请开启此项" data-toggle="tooltip" data-placement="top"></i>
+                                        </td>
+                                        <td class="value">
+                                            <label for="avatar_query_string">
+                                                <input {{ (Option::get('avatar_query_string') == '1') ? 'checked="true"' : '' }} type="checkbox" id="avatar_query_string" name="avatar_query_string" value="1"> 为头像添加 Query String
+                                            </label>
+                                        </td>
+                                    </tr>
+
                                     <tr>
                                         <td class="key">评论代码
                                             <i class="fa fa-question-circle" title="就是 Disqus，多说，畅言等评论服务提供的代码。留空以停用评论功能" data-toggle="tooltip" data-placement="top"></i>
diff --git a/resources/views/index.tpl b/resources/views/index.tpl
index 3a9bebee..8fc762ab 100644
--- a/resources/views/index.tpl
+++ b/resources/views/index.tpl
@@ -50,14 +50,14 @@
                                     <!-- Menu Toggle Button -->
                                     <a href="#" class="dropdown-toggle" data-toggle="dropdown">
                                         <!-- The user image in the navbar-->
-                                        <img src="./avatar/25/{{ base64_encode($_SESSION['email']) }}.png" class="user-image" alt="User Image">
+                                        <img src="./avatar/25/{{ Utils::getAvatarFname($user) }}" class="user-image" alt="User Image">
                                         <!-- hidden-xs hides the username on small devices so only the image appears. -->
-                                        <span class="hidden-xs nickname">{{ ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName() }}</span>
+                                        <span class="hidden-xs nickname">{{ Utils::getNameOrEmail($user) }}</span>
                                     </a>
                                     <ul class="dropdown-menu">
                                         <!-- The user image in the menu -->
                                         <li class="user-header">
-                                            <img src="./avatar/128/{{ base64_encode($_SESSION['email']) }}.png" alt="User Image">
+                                            <img src="./avatar/128/{{ Utils::getAvatarFname($user) }}" alt="User Image">
                                             <p>{{ $_SESSION['email'] }}</p>
                                         </li>
                                         <!-- Menu Footer-->
diff --git a/resources/views/skinlib/master.tpl b/resources/views/skinlib/master.tpl
index 1c12f387..77146a6c 100644
--- a/resources/views/skinlib/master.tpl
+++ b/resources/views/skinlib/master.tpl
@@ -84,14 +84,14 @@
                                     <!-- Menu Toggle Button -->
                                     <a href="#" class="dropdown-toggle" data-toggle="dropdown">
                                         <!-- The user image in the navbar-->
-                                        <img src="../avatar/25/{{ base64_encode($_SESSION['email']) }}.png" class="user-image" alt="User Image">
+                                        <img src="../avatar/25/{{ Utils::getAvatarFname($user) }}" class="user-image" alt="User Image">
                                         <!-- hidden-xs hides the username on small devices so only the image appears. -->
-                                        <span class="hidden-xs nickname">{{ ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName() }}</span>
+                                        <span class="hidden-xs nickname">{{ Utils::getNameOrEmail($user) }}</span>
                                     </a>
                                     <ul class="dropdown-menu">
                                         <!-- The user image in the menu -->
                                         <li class="user-header">
-                                            <img src="../avatar/128/{{ base64_encode($_SESSION['email']) }}.png" alt="User Image">
+                                            <img src="../avatar/128/{{ Utils::getAvatarFname($user) }}" alt="User Image">
                                             <p>{{ $_SESSION['email'] }}</p>
                                         </li>
                                         <!-- Menu Footer-->
diff --git a/resources/views/user/master.tpl b/resources/views/user/master.tpl
index 0f07dcd2..e1912d15 100644
--- a/resources/views/user/master.tpl
+++ b/resources/views/user/master.tpl
@@ -48,12 +48,12 @@
                             <a href="#" class="dropdown-toggle" data-toggle="dropdown">
                                 <i class="fa fa-user"></i>
                                 <!-- hidden-xs hides the username on small devices so only the image appears. -->
-                                <span class="hidden-xs nickname">{{ ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName() }}</span>
+                                <span class="hidden-xs nickname">{{ Utils::getNameOrEmail($user) }}</span>
                             </a>
                             <ul class="dropdown-menu">
                                 <!-- The user image in the menu -->
                                 <li class="user-header">
-                                    <img src="../avatar/128/{{ base64_encode($_SESSION['email']) }}.png" alt="User Image">
+                                    <img src="../avatar/128/{{ Utils::getAvatarFname($user) }}" alt="User Image">
                                     <p>{{ $_SESSION['email'] }}</p>
                                 </li>
                                 <!-- Menu Footer-->
@@ -80,10 +80,10 @@
                 <!-- Sidebar user panel (optional) -->
                 <div class="user-panel">
                     <div class="pull-left image">
-                        <img src="../avatar/45/<?php echo base64_encode($_SESSION['email']); ?>.png" alt="User Image">
+                        <img src="../avatar/45/{{ Utils::getAvatarFname($user) }}" alt="User Image">
                     </div>
                     <div class="pull-left info">
-                        <p class="nickname">{{ ($user->getNickName() == '') ? $_SESSION['email'] : $user->getNickName() }}</p>
+                        <p class="nickname">{{ Utils::getNameOrEmail($user) }}</p>
                         <i class="fa fa-circle text-success"></i> Online
                     </div>
                 </div>
diff --git a/setup/options.php b/setup/options.php
index ba0a5bf5..c6f99caf 100644
--- a/setup/options.php
+++ b/setup/options.php
@@ -3,7 +3,7 @@
  * @Author: printempw
  * @Date:   2016-07-29 11:53:11
  * @Last Modified by:   printempw
- * @Last Modified time: 2016-07-29 13:35:57
+ * @Last Modified time: 2016-08-07 16:43:16
  */
 
 return [
@@ -28,5 +28,6 @@ return [
     'sign_score'               => '10,100',
     'score_per_storage'        => '1',
     'score_per_player'         => '100',
-    'sign_after_zero'          => '0'
+    'sign_after_zero'          => '0',
+    'avatar_query_string'      => '0'
 ];