Abstract: The orographic precipitation equation proposed by Smith (1979) is improved in the present study to solve the problem that the typhoon precipitation predicted by the ECMWF model is significantly smaller than actual precipitation under complex terrain condition. It is proposed that the height of the saturated moist layer is used as the upper bound of the equation integral, and different precipitation efficiencies are specified for different terrain elevations; the dimensionless wet Froude number greater than 1 is used as the criterion for orographic precipitation. The precipitation correction method is applied to correct the precipitation of Typhoon Megi (typhoon 1617) predicted by the ECMWF mode. The results show that although there exists obvious false prediction in some small-scale terrain areas, significant correction effect is found for strong precipitation in large-scale terrain areas. Further application of the correction method on precipitation forecast of typhoons 1513, 1521 and 1614 shows that the correction method of orographic precipitation on the windward slope can significantly improve the prediction of typhoon extreme precipitation, which has great implications for disaster prevention and mitigation.It is necessary to point out that the orographic precipitation correction method used in the present study only considers orographic precipitation under stable condition, and its application in other cases needs further study.