Most automatic weather stations use a Gray code disc wind direction sensor,and in the new stations in Hebei Province, there are two types of wind direction sensors (DZZ4 and DZZ5), and the Gray code is used as the output mode of thses direction sensors, but the two models have different power supply modes, and the indications of error directions when failures are actually detected are different. According to the wind coding principles of values corresponding to the codes for Gray code disc winddirection sensors, the regularity of wind sensor error direction indication values are studied. The method can be used to realize the quick detection of direction sensor onsite maintenance, which is simple, especially for single Gray fault identification, convenient, and more suitable for stationlevel maintenance, especially for the general onsite repair in the absence of testing equipment and instruments.