Abstract: According to the coordinate time series results of 19 CMONOC reference stations in Gansu Province, the maximum likelihood estimate (MLE) was used to explore the optimal noise model of each reference station, the velocity field of the reference station was determined, and the crustal movement in Gansu Province was analyzed. The research results show that the noise characteristics of each coordinate component of the CMONOC reference station in Gansu Province are quite different. "WN+FN" is the optimal noise model, which can better describe the noise characteristics of the three components of the reference station coordinate time series, and The estimated rate uncertainty is 4 to 15 times when only white noise is considered. The average rate of horizontal movement of the CMONOC reference station in Gansu Province under the framework of ITRF14 is 34.54 mm/a and the direction of movement is SEE 98.07°; the average rate of horizontal movement relative to the Eurasian plate is 6.49 mm/a and the direction of movement is NEE 79.23‬°.