diff --git a/apps/enm/tasks.py b/apps/enm/tasks.py
index 70aba207..dde29813 100644
--- a/apps/enm/tasks.py
+++ b/apps/enm/tasks.py
@@ -123,7 +123,7 @@ def cal_mpointstat_hour(mpointId: str, year: int, month: int, day: int, hour: in
                     val = last_val - first_val
                 else:
                     # 这里判断有可能清零了
-                    max_val = mrs.aggregate(max=Max(f'val_{val_type}'))["max"]
+                    max_val = max(mrs.aggregate(max=Max(f'val_{val_type}'))["max"], first_val)
                     val = max_val - first_val + last_val
         elif mpoint.type == Mpoint.MT_COMPUTE and mpoint.formula:
             formula = mpoint.formula