Abstract: The tropospheric mapping function is an important model for transforming the zenith tropospheric delay into the total delay on the signal propagation path. Choosing an appropriate mapping function is of great significance for retrieving the accuracy of atmospheric precipitation water vapor(PWV). In this paper, the influence of tropospheric mapping function on the inversion of atmospheric PWV accuracy is studied. Select three kinds of mapping functions, VMF1, GMF and NMF, and use GAMIT software to compare the three mapping functions in different seasons and different altitudes. Retrieving the accuracy impact of atmospheric PWV. The results show that the inversion accuracy of the GMF function model with 10° elevation angle as the solution cutoff height angle is the best when the atmospheric precipitation is inverted, Which provides a reference for further improving the real-time accuracy of GNSS atmospheric water vapor inversion.