Aimed at the problem that the channel of widerange AirtoGround communication is hard to be exactly described by adoting traditional model of channel, according to the height of flight platform, the Markov Process is utilized as exactly as possible to describe AirtoGround fading channel from the switch of the improved Rice model and Loo model. In the meantime, every model is divided into slight and heavy occlusion states, and the Markov Process is used to switch for the two different environment states according to special local environment. Getting rid of the ideal assumption that incident angles of arrival wave from multipath are submitted to uniform distribution in , then two relevant and real Gaussian models are constructed as a Rice process, the Rice model and Loo model are modified and optimized, the Doppler power spectrum and Amplitudephase Probability Density Function of the two models after modification are deduced. The simulation results show that the curve of Doppler power spectrum should be the unsymmetrical form after modification, the degree of freedom (DOF) and adaptability of the model are enhanced, the different influence to signal transmission in different channel states is distinctly depicted, and this can reflect the real conditions well.