Abstract:GAMIT/GLOBK has been used to process the data of 43 GNSS continuous stations in Yunnan since 2018-2021 to obtain the time series. We use Kriging interpolation method to calculate and obtain the strain rate field and analyze the variation of regional strain field before and after the Yangbi MS6.4 earthquake. The results show that the seismic risk area should be focused on the compression area of surface strain and the conversion area of high and low values of maximum shear strain. The Yangbi MS6.4 earthquake occurred in the compression area of surface strain in the early stage, and quickly changed to extension state after the earthquake. Yangbi area has been in the high value area of maximum shear strain rate for a long time, and the shear activity is strong. The regional strain accumulation rate of maximum shear strain near the epicenter decreases rapidly in the short-term before the earthquake.