Abstract: To evaluate the quality of wind profiler radar data in Guizhou, this study selects sounding observation data from Guizhou and its surrounding areas, and verifies the reliability of horizontal wind fields in the European Centre for Medium-Range Weather Forecasts Fifth Generation Global Atmospheric Reanalysis (ERA5) through comparative analysis of error characteristic parameters. On this basis, this study adopts ERA5 reanalysis data to evaluate the quality of hourly horizontal wind field data from three tropospheric wind profiler radars (Guiyang, Weining, and Pu'an) in Guizhou. The results indicate that: (1) ERA5 exhibits small standard deviations and mean biases of horizontal wind errors compared with sounding data, demonstrating its applicability for validating the accuracy of wind profiler radar horizontal wind data in Guizhou. (2) The quality of wind profiler radar data is significantly improved with the improvement of quality control levels. Under equivalent quality control, the meridional (south-north, V) component shows better precision than the zonal (east-west, U) component, and the U component presents obvious station differences (Weining performs best, Guiyang performs poorest). (3) Precipitation exerts a great impact on the quality of wind profiler horizontal wind data, especially at heights above 2 km, where precipitation increases the error standard deviations by approximately 1 m/s. (4) The quality of wind profiler horizontal wind data displays seasonal variations (highest in summer, poorest in winter). The U component has larger seasonal differences than the V component, with minor diurnal fluctuations. In contrast, the V component exhibits a relatively large diurnal difference at altitudes of 2~4 km.