diff --git a/src/pages/battle-room.vue b/src/pages/battle-room.vue
index 03de5dd..36f0b1c 100644
--- a/src/pages/battle-room.vue
+++ b/src/pages/battle-room.vue
@@ -263,19 +263,18 @@ const shareTitle = computed(() => {
 });
 
 /**
- * 根据对战类型动态返回分享封面图路径
- * battleType === 2（多人乱斗）→ melee_share.jpg
- * 其余（好友约战 / 组队对战）→ contest_share.jpg
+ * 根据对战类型和靶纸尺寸动态返回分享封面图路径，共 4 张图：
+ *   contest_share_20.jpg — 约战/对抗赛 + 20cm 靶
+ *   contest_share_40.jpg — 约战/对抗赛 + 40cm 靶
+ *   melee_share_20.jpg   — 多人乱斗 + 20cm 靶
+ *   melee_share_40.jpg   — 多人乱斗 + 40cm 靶
  *
- * 网络图片：
- *   https://static.shelingxingqiu.com/shootmini/static/share/melee_share.jpg
- *   https://static.shelingxingqiu.com/shootmini/static/share/contest_share.jpg
+ * 当 targetSize 未知时默认取 20cm 图。
  */
 const shareImage = computed(() => {
-  if (room.value.battleType === 2) {
-    return 'https://static.shelingxingqiu.com/shootmini/static/share/melee_share.jpg';
-  }
-  return 'https://static.shelingxingqiu.com/shootmini/static/share/contest_share.jpg';
+  const type = room.value.battleType === 2 ? 'melee' : 'contest';
+  const size = targetSize.value === 40 ? '40' : '20';
+  return `https://static.shelingxingqiu.com/shootmini/static/share/${type}_share_${size}.jpg`;
 });
 
 onShareAppMessage(() => {