In order to study the applicability of the elevation model with considering terrain fluctuation factor in the calculation of the atmospheric water vapor conversion coefficient, this article selects different elevation data for five years from Xinjiang region sounding stations, using elevation model and Emardson model without considering the terrain fluctuation to calculate water vapor conversion coefficient K, and analyzing the applicability of the elevation model in Xinjiang region where is a large area of terrain, then comparing the accuracy of the conversion coefficient between the same latitude and different elevations as well as between the same elevation and different latitudes by the elevation model, researching the influence on elevation model from station’s latitude and altitude. The research shows that: (1) Adding terrain fluctuation factor of elevation model and Emardson model without considering the effects of elevation will appear the phenomenon of increasing accuracy, and precision of elevation model is slightly better than that of Emardson model with station’s altitude increasing. (2) When latitude acts as influence factor, the lower latitude the measuring station is, the higher accuracy of the elevation model will be. When elevation acts as influence factor, the bigger elevation the measuring station is, the higher accuracy of the elevation model will be. (3) The applicability of elevation model is better in these regions which located in low latitude and high altitude.