diff --git a/ef_course_autopilot.py b/ef_course_autopilot.py
index 49d26ff..d2ba6c6 100755
--- a/ef_course_autopilot.py
+++ b/ef_course_autopilot.py
@@ -883,6 +883,60 @@ class EFCourseAutopilot:
             self._log(f"下一单元已激活 (status={put_resp.status_code})")
             return True
 
+        if is_completed and not next_unit_id:
+            self._log("当前等级所有单元已完成，尝试切换至下一等级")
+            try:
+                levels_url = f"{self.base_url}/wl/api/change-level/levels"
+                levels_resp = self.session.get(
+                    levels_url, params={"locale": self.locale},
+                    headers=headers, timeout=REQUEST_TIMEOUT,
+                )
+                levels_resp.raise_for_status()
+                levels_data = levels_resp.json()
+
+                current_level_id = levels_data.get("currentLevelId")
+                levels = levels_data.get("levels", [])
+                if not current_level_id or not levels:
+                    self._log("无法获取等级信息，跳过等级切换")
+                    return False
+
+                # 找到 currentLevelId 之后的第一个未开始的等级
+                found_current = False
+                next_level = None
+                for level in levels:
+                    lid = level.get("id") or level.get("levelId")
+                    if not found_current:
+                        if lid == current_level_id:
+                            found_current = True
+                        continue
+                    status = level.get("progress", {}).get("status", "")
+                    if status == "not_started":
+                        next_level = level
+                        break
+                    if status == "started":
+                        next_level = level
+                        break
+
+                if next_level:
+                    next_level_id = next_level.get("id") or next_level.get("levelId")
+                    self._log(f"切换至下一等级 (levelId={next_level_id})")
+                    study_plan_url = f"{self.base_url}/wl/api/study-plan/study-plan"
+                    put_resp = self.session.put(
+                        study_plan_url,
+                        params={"locale": self.locale},
+                        json={"courseId": self.ctx.course_id, "levelId": next_level_id},
+                        headers=headers, timeout=REQUEST_TIMEOUT,
+                    )
+                    put_resp.raise_for_status()
+                    self._log(f"等级切换成功 (status={put_resp.status_code})")
+                    return True
+                else:
+                    self._log("未找到可切换的下一等级")
+            except Exception as e:
+                self._log(f"等级切换失败: {e}")
+
+            return False
+
         return False