It is urgent to establish the attenuation relationship of ground motion parameters for the seismic disaster prevention in China. Southwest China was taken as the study area, and all the strong ground motion records from 2008 to 2022 were collected. The data collected was processed to form the dataset supporting. Using strong ground motion records from the 2014 Ludian Earthquake and the 2022 Luding Earthquake to analyze the applicability in southwest China of five GMPE (ground motion prediction equations) with high applicability. The results show that the CB14 model performs better for the estimation of short period ground motions, and the Z16 model performs better for the estimation of medium and long period ground motions. The Z16 model as well as the CB14 model were referred to for the improvement of the equations, so as to establish a horizontal GMPE that is more suitable for southwest China. The coefficients in the equation were fitted using a two-step regression as well as a random effects approach. The applicability of the GMPE developed for southwest China was verified by performing residual analysis and comparing it with existing attenuation relationships.Ultimately, it can be found that the updated GMPE is more applicable to southwest China.