diff --git a/src/components/olmap/ContaminantSimulation/AnalysisParameters.tsx b/src/components/olmap/ContaminantSimulation/AnalysisParameters.tsx
index b23c8d2..9bb134a 100644
--- a/src/components/olmap/ContaminantSimulation/AnalysisParameters.tsx
+++ b/src/components/olmap/ContaminantSimulation/AnalysisParameters.tsx
@@ -175,6 +175,10 @@ const AnalysisParameters: React.FC = () => {
       ? startTime.format("YYYY-MM-DDTHH:mm:00Z")
       : "";
     try {
+      if (!pattern) {
+        setPattern("CONSTANT");
+        console.log("默认设置 pattern 为 CONSTANT");
+      }
       const params = {
         network,
         start_time: start_time,