diff --git a/business/jxstore/report/report.go b/business/jxstore/report/report.go
index cb0c86646..4cb8acc52 100644
--- a/business/jxstore/report/report.go
+++ b/business/jxstore/report/report.go
@@ -468,6 +468,6 @@ func CalculateCoverArea(coordinate []string) (area float64) {
 		sum += (xyList[i+1][0] - xyList[i][0]) * (xyList[i+1][1] + xyList[i+1][1])
 	}
 	sum += (xyList[0][0] - xyList[len(xyList)-1][0]) * (xyList[0][1] + xyList[len(xyList)-1][1])
-	sum /= 2
+	sum /= float64(2)
 	return math.Round(sum)
 }