Abstract: Based on the grid precipitation forecast of Southwest Center WRF ADAS Real-time Modeling System, the terrain precipitation correction equation is constructed by calculating the terrain precipitation estimation. 11 heavy precipitation processes occurred in the transition zone of the eastern slope of the Western Sichuan Plateau from June to August 2020 are corrected by using the model and actual terrain correction schemes respectively. The results show that: Compared with the model forecasts, the average TS scores of precipitation forecasts of various levels were improved after the application of the model terrain correction, and the TS scores of heavy rain and above were increased by more than 4%, the average false alarm rate and fail rate were both reduced. The correction effect was better than that of the actual terrain correction. This method had universal applicability, for the complex terrain on the eastern slope of the Western Sichuan Plateau, the Panxi River Valley and the western mountainous areas of the Basin, it was applicable to alternative precipitation processes which were similar or dissimilar to the forecast and the actual situation, as well as strong or weak precipitation processes.