The automatic weather station is a realtime surface meteorological observation system, it is important to locate the fault quickly and recovery in time when the automatic weather station fails. But it often takes a long time to find the fault, because of the lack of a certain detection equipment. In this paper, a portable detector is designed for automatic weather stations, which can quickly detect the faults of temperature, humidity, rainfall, wind direction, wind speed, pressure, visibility, evaporation sensors, fiber, and cable. Users can directly check the current observation data and operating status of the automatic weather station on the instruments LCD screen. The detector can locate the fault point quickly in the automatic weather station observation system, shorten the recovery time, improve the maintenance capabilities of the technical staff, and has a high potential in application.