The geological structure of the northwest Yunnan is complicated, and the strong earthquake preparation background is remarkable.In this paper, the crustal strain rate fields are calculated using GPS observation data in different periods（1999~2007 and 2013~2018）in northwest Yunnan, and the dynamic evolution characteristics of the strain rate fields are analyzed. Then, the GPS observation data is used as boundary constraints, and based on the block loading method, we simulated the kinematic characteristics and stress accumulation rate of the main fault zones in northwest Yunnan. Finally, combining historical strong earthquakes such as the Wenchuan and the Lushan and nearfield crossfault observation data, we discuss the crustal deformation characteristics and deformation mechanism in the northwest Yunnan. The results showed that the current crustal deformation in the northwest Yunnan is characterized by roughly E—Wdirected extension and N—Sdirected compression, as well as SW—NEdirected shear deformation. The crustal strain rate fields had experienced dynamics adjustment at different periods, but the direction of the maximum principal compressive strain did not change in two periods, all of which were NNWdirected. Before the Wenchuan earthquake, the movement rate and the nature of the main fault zones in northwest Yunnan were consistent with the existing geological and deformation results. After the Wenchuan earthquake, the movement properties and stress states of some fault zones have changed. In this paper, we suggest that this is related to the occurrence of strong earthquakes in the far field such as the Wenchuan and the moderate strong earthquakes in the near field. These earthquakes have some effects on the local stress fields, which is one of the reasons for the changes of the movement properties of some faults.