n view of the abnormal minute precipitation data from some conventional ground observation stations in Guizhou Province in June 2020, which led to the problem of abnormally large precipitation during the flood season, this paper conducts precipitation anomalies from the aspects of instrumental observation, observation environment, human interference and electromagnetic interference. Troubleshooting work, and provide corresponding solutions according to the cause of the failure. In order to provide a reference for controlling the quality of meteorological data, guaranteeing and maintaining meteorological observation instruments.