Abstract: As the nearest neighbor of earth, Mars has always been the first choice for space exploration and development of human beings. Landing on Mars, establishing a base and developing and utilizing resource are the primary goal of Mars exploration, but the establishment of Mars base needs to solve the issue of power supply first. The nuclear reactor power has the advantages of high power, long service life and environmental tolerance ability, and it is an ideal energy solution option for Mars base and other deep space exploration missions. A brief analysis of the current status of energy that can be used for a Mars base was carried out. The overall scheme of 40 kWe nuclear reactor power for Mars surface was given. Finally, the power scheme was analyzed and demonstrated from the aspects of reactor physics, critical safety, shielding, thermal and structure. The results show that the nuclear reactor power scheme is reasonable and feasible. It can meet the requirements of safety and lifetime.