Abstract: A Mars probe will be in the near Earth environment, the interplanetary environment and the Mars environment in turns. This paper analyzes the characteristics of the space environments in the whole process of the Mars exploration mission, including the launch stage, the Earth-Mars transfer stage, the Mars surrounding stage, and the landing and the ranging on the Martian surface, and compares them with the space environment encountered by Earth satellites. In view of the characteristics of the Mars missions, the space environmental effects such as the total ionizing dose effect, the single event effect, the deep dielectric charging, the solar irradiation and the low-pressure Martian atmosphere and the Martian dust are analyzed for different mission profiles. Key points in the space environmental protection design for the Mars probe are highlighted.