Abstract：Based on the continuous observation data of GNSS in Yunnan since January 2018, the displacement field is obtained by high-precision data processing software (GAMIT/GLOBK), and the Kriging interpolation method is used to mesh the interpolation to obtain uniform distribution. We ascertain the displacement field, calculate strain, obtain surface strain information, dynamically analyze the surface strain variation characteristics of Yunnan in 2018, and explore the intrinsic relationship between the two M5.0 earthquakes in Tonghai and Mojiang M5.9 earthquake. The results show that there are significant backgrounds of strain accumulation before the two M5.0 earthquakes in Tonghai and Mojiang M5.9 earthquake, and there is a process of regional strain field adjustment in the short term before the earthquake. The two may be strong tensile and strong compression regional strains under the dual factors, the product of the changing process. The difference is that the Mojiang M5.9 earthquake changed the regional characteristics of strong extrusion and strong tensile joints bounded by the Shuangbai-Xinping-Mojiang strip, which had a substantial impact on the overall regional surface strain pattern in Yunnan.