With the development of socio-economy and technology, more and more people from various countries pay more attention to deep-space exploration. Mars is the closest planet where life is possible. So, Mars exploration is a hot issue on international deep space exploration in recent years. There are many advantages for the use of unmanned aerial exploration vehicles on Mars, including the wide range of exploration, the visualization of terrain changes, etc. In this paper, the overall mission planning is described for unmanned aerial exploration vehicle on Mars, and the difference between flight on earth and on Mars is discussed. Then the longitudinal nonlinear model is established for unmanned aerial exploration vehicle on Mars, and Taylor expansion is applied to the nonlinear model at the trim point, hence to obtain the linear model. By further analysis of the linear model, the stable performance and flight characteristics have been grasped for unmanned aerial exploration vehicle on Mars. These work will provide the platform for the follow-up research for Mars Unmanned Aerial Vehicle (UAV) navigation and control method.