diff --git a/plugins/sentinel/dashboard.html b/plugins/sentinel/dashboard.html
index 27b1af5..9020053 100644
--- a/plugins/sentinel/dashboard.html
+++ b/plugins/sentinel/dashboard.html
@@ -260,7 +260,9 @@
               if (charts.net) {
                 var rx = net.rx_bytes_sec||0, tx = net.tx_bytes_sec||0;
                 charts.net.update(rx, tx);
-                charts.net.maxVal = Math.max(charts.net.maxVal, 1024);
+                // 惰性量程: 仅当数据超过当前上限才扩大
+                var curMax = Math.max(rx, tx, 100);
+                if (curMax > charts.net.maxVal) charts.net.maxVal = curMax;
               }
             } catch(e) {}
           }