Abstract: We obtained the data of mountain-based GPS radio occultation and statistically analyzed the occultation events based on the GPS occultation observation experiment on Mt. Tailao of Fujian Province and Mt. Heding of Zhejiang Province. This paper describes an algorithm and principle of calculating atmospheric refractivity and arrival angle. The directly refraction model and the reflection model of radio wave propagation are used to calculate the arrival angle between any two points by using the mountain-based inversion data and European Centre for Medium-range Weather Forecasts(ECMWF) data to construct the refractivity model. The results show that the inversion accuracy of the atmospheric refractivity profiles is above 95%, and the direct refraction model based on the mountain-based inversion data is better than the reflection model in the short distance calculation at 1 km. The arrival angle model of the mountain-based inversion data is superior to the ECMWF data model. The two types of angle-of-arrival calculation models has important guiding significance on simulating the propagation path between two points and the reception and adjustment of the real radio signal.