Abstract: In this paper, a new method for GPS height fitting by using the Combined Model is presented, which is based on the analysis of common models for GPS height fitting.In the method, 1 StOpt software is used as a tool, fitting absolute error square minimum is the target while different weights are given for fitting of surface model and the fitting model for multiple surface function.As a result, a new model of fitting is formed, GPS elevation fitting based on combined model is realized on the whole area.Relative data analysis based on the complied program is conducted.The results indicate that the accuracy can be improved in some extent, and it can be used in engineering practice.