Through checking missing data， climate limits， historical extreme values， time and space consistency， trend curve， etc.， an analysis is made of the quality of automatic weather stations data (including visibility， humidity， temperature， surface temperature， and wind) from the Huabei expressway in Tianjin It is found out that the main problem for the automatic weather stations on expressways is data missing， too small variability or constant data within a certain time (generated by equipment failures) In rare cases， there exist error data outside the climate limits By means of the trend analysis method，suspicious data are analyzed by checking the history values， time consistency， etc.， and the results indicate that the error rate of suspicious data is generally acceptable， and the currently used thresholds need to be improved continuously