diff --git a/services/sensor/src/sensor_dump.cpp b/services/sensor/src/sensor_dump.cpp
index 0137ba0a34fdcf609029902a08cf298c4f908c4d..cd5c0fb94ae08c2c6f94ae65f611a885f5f21df8 100644
--- a/services/sensor/src/sensor_dump.cpp
+++ b/services/sensor/src/sensor_dump.cpp
@@ -85,7 +85,7 @@ void SensorDump::ParseCommand(int32_t fd, const std::vector<std::string> &args,
             continue;
         }
         if (str.find("-") == 0) {
-            count += str.size() - 1;
+            count += static_cast<int32_t>(str.size()) - 1;
             continue;
         }
     }