Abstract: Based on the ground observation data of 105 national basic meteorological stations in Xinjiang and the sounding data of 14 stations from 2019 to 2021, the applicability of ERA5 and FNL data in Xinjiang was compared and evaluated. The results show that the applicability of sea level pressure, 2 m temperature, 2 m dew point temperature and 10 m wind field of ERA5 data is better than that of FNL data, and the applicability of 2 m temperature is better than that of other elements. There are significant seasonal differences in the applicability of sea level pressure, 2 m temperature and 2 m dew point temperature. Among the high-altitude elements, the applicability of FNL data to geopotential height and dew point temperature is better than that of ERA5 data, while the applicability of ERA5 data to wind field and temperature is better. At different height levels, the applicability of the two sets of data is better below 300 hPa than above 300 hPa.