In this paper, the accuracy of the TRMM 3B42 satellite precipitation data was tested in the annual, quarterly, monthly and daily timescales using the observed data from the 19 meteorological stations, and the ability of TRMM 3B42 to detect different levels of precipitation wasdiscussed, so as to analyze the applicability of the TRMM data for Guizhou. The results show that TRMM 3B42 precipitation data are better in theannual scale (R = 0.82). The average relative error of the 19 stations in the study area is -2.39%, of which nearly 70% of the site data show that theTRMM 3B42 precipitation is lower than that from the ground meteorological stations. The overall correlation coefficient is very good in the monthscale (R = 0.89). However, the TRMM 3B42 satellite data have different detection capabilities for different seasons. Among them, the winter fittingcoefficient is the lowest. In the daily scale, the precipitation data of TRMM 3B42 are different from the actual precipitation, and the precipitationintensity is too large or too small to detect accurately. For a single site, the low-altitude site TRMM satellites detect a small deviation from the observedprecipitation.