In order to solve the space-time discontinuity problem of unmanned aerial vehicle（UAV） non-stationary channel parameters， this paper proposes a non-stationary geometric stochastic model of UAV that supports three-dimensional motion and posture rotation， which is used to describe and simulate the real characteristics of UAV multiple-input multiple-output communication channel. Based on the concept of “accurate qualitative” in QuaDRiGa， the model update time-varying channel parameters based on the topological relation of receiver and transmitter， improve the channel power calculation method considering the probability of path birth and death， and introduce posture phase matrix to describe UAV posture rotation， so as to realize smooth evolution of UAV non-stationary channel parameters. The numerical simulation results show that the model proposed in this paper can ensure the smooth evolution of parameters such as power and angle， and the autocorrelation function of the output channel is non-stationary and significantly affected by UAV posture. The proposed model can be used in UAV communication system design and algorithm optimization.