Abstract: In this paper ,aiming at the characteristics of the site coordinates of the continuously operating reference stations (CORS) in Sichuan-Tibet region containing complex influence factors and abundant and weak beneficial signals ,in order to solve the problem that the regional large-scale time series data analysis and processing process is cumbersome and cannot be processed in large quantities, this paper designs and develops a GNSS coordinate time series preprocessing system, which supports the multi-site batch solving mode of large area, realizes data product preprocessing, download and visualization, and realizes least squares fitting, coarse rejection, and integration of integrated functional modules such as modeling interpolation and common-mode error correction. The long-term coordinate time series data of the crustal movement observation network of China (CMONOC) is used to evaluate the performance of the software from the aspects of solution accuracy and efficiency. The results show that the goodness of fit R² of the least squares fitting in the N direction and E direction of each station in the CMONOC is about 99%, and the fitting effect is good. The WRMS values of the time series after coarse rejection are lower than those in all directions before rejection. The RMSE values of the results after horizontal interpolation are better than 8 mm. After the common-mode error is removed, the RMS values in both the horizontal and vertical directions decrease.