diff --git a/src/app/ContestSite/ArenaPage.tsx b/src/app/ContestSite/ArenaPage.tsx
index 44f1c7c8e..006ef0516 100644
--- a/src/app/ContestSite/ArenaPage.tsx
+++ b/src/app/ContestSite/ArenaPage.tsx
@@ -185,11 +185,11 @@ const ArenaPage: React.FC<ContestProps> = ({ mode, user }) => {
           const firstImage = imageFiles[0];
           return getAvatarUrl(firstImage.Key);
         } else {
-          return "/UserOutlined.png";
+          return `https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${userId}`;
         }
       } catch (error) {
         console.error("Failed to load avatar:", error);
-        return "/UserOutlined.png";
+        return `https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${userId}`;
       }
     };
 
diff --git a/src/app/ShareSite/CoursePage/DiscussDrawer.tsx b/src/app/ShareSite/CoursePage/DiscussDrawer.tsx
index 85dbf6335..5afee3b92 100644
--- a/src/app/ShareSite/CoursePage/DiscussDrawer.tsx
+++ b/src/app/ShareSite/CoursePage/DiscussDrawer.tsx
@@ -291,7 +291,7 @@ const DiscussDrawer: React.FC<CourseProps> = ({
         const imageFiles = files.filter((file) =>
           /\.(jpe?g|png)$/i.test(file.Key),
         );
-        let avatarUrl = "/UserOutlined.png";
+        let avatarUrl = `https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${userId}`;
         if (imageFiles.length > 0) {
           const firstImage = imageFiles[0];
           avatarUrl = await getAvatarUrl(firstImage.Key);
@@ -302,7 +302,7 @@ const DiscussDrawer: React.FC<CourseProps> = ({
         return avatarUrl;
       } catch (error) {
         console.error("Failed to load avatar:", error);
-        return "/UserOutlined.png";
+        return `https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${userId}`;
       }
     };
 
diff --git a/src/app/UserSite/ProfilePage.tsx b/src/app/UserSite/ProfilePage.tsx
index 6be350b6f..949d5cf22 100644
--- a/src/app/UserSite/ProfilePage.tsx
+++ b/src/app/UserSite/ProfilePage.tsx
@@ -86,7 +86,7 @@ const ProfilePage: React.FC<UserProps> = ({ mode, user, setUser }) => {
               message.error("加载头像失败");
             });
         } else {
-          setImageUrl("/UserOutlined.png"); // 替换为实际的默认头像 URL
+          setImageUrl(`https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${user.uuid}`); // 替换为实际的默认头像 URL
         }
       })
       .catch((error) => {
diff --git a/src/app/index.tsx b/src/app/index.tsx
index 8b55f2d76..3a2c0efa6 100644
--- a/src/app/index.tsx
+++ b/src/app/index.tsx
@@ -88,7 +88,7 @@ const App: React.FC = () => {
             const firstImage = imageFiles[0];
             return getAvatarUrl(firstImage.Key);
           } else {
-            setImageUrl("/UserOutlined.png"); // 替换为默认头像 URL
+            setImageUrl(`https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${user.uuid}`); // 替换为默认头像 URL
             return null;
           }
         })
@@ -501,7 +501,7 @@ const App: React.FC = () => {
             const firstImage = imageFiles[0];
             return getAvatarUrl(firstImage.Key);
           } else {
-            setImageUrl("/UserOutlined.png"); // 替换为默认头像 URL
+            setImageUrl(`https://api.dicebear.com/9.x/thumbs/svg?scale=80&backgroundType=gradientLinear&seed=${user.uuid}`); // 替换为默认头像 URL
             return null;
           }
         })