diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_turn_stream.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_turn_stream.rs
index 4b9bdbfb7..5bbdb7d20 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_turn_stream.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_turn_stream.rs
@@ -211,13 +211,16 @@ fn merge_stream_snapshot(
             .map(Iterator::count)
             .unwrap_or_default()
     };
+    // 文本段按"更长优先"：同一个 item 的文本只会增长，而快照的 updated_at 未必单调递增；
+    // 只认 updated_at 更新会把后到的完整文本丢掉（实机表现：正文只剩前缀"我来"）。
     let take_incoming = incoming.updated_at > existing.updated_at
+        || (incoming.kind == "text" && text_len(incoming) > text_len(existing))
         || (incoming.updated_at == existing.updated_at && text_len(incoming) > text_len(existing));
     let mut merged = existing.clone();
     if take_incoming {
         merged.text = incoming.text.clone();
-        merged.updated_at = incoming.updated_at;
     }
+    merged.updated_at = merged.updated_at.max(incoming.updated_at);
     if merged.call_id.is_none() {
         merged.call_id = incoming.call_id.clone();
     }
diff --git a/apps/ai-game-creator-shell/src/App.tsx b/apps/ai-game-creator-shell/src/App.tsx
index 00eb59762..78cb692fb 100644
--- a/apps/ai-game-creator-shell/src/App.tsx
+++ b/apps/ai-game-creator-shell/src/App.tsx
@@ -550,8 +550,12 @@ function mergeTurnStreamItems(
     // 内容只在更新（或同刻更长）的快照上替换；`seq` 取最早，位置不许回退。
     const textLength = (value: TurnStreamItem) =>
       value.kind === 'text' ? (value.text?.length ?? 0) : 0;
+    // 文本段按"更长优先"：同一个 item 的文本只会增长，而快照的 updatedAt 未必单调递增；
+    // 只认 updatedAt 更新会把后到的完整文本丢掉（实机表现：正文只剩前缀"我来"）。
     const takeIncoming =
       normalized.updatedAt > previous.updatedAt ||
+      (normalized.kind === 'text' &&
+        textLength(normalized) > textLength(previous)) ||
       (normalized.updatedAt === previous.updatedAt &&
         textLength(normalized) > textLength(previous));
     byId.set(id, {