Because of the extremely low density and low heat capacity of the Martian atmosphere， the atmospheric pressure and atmospheric density of Mars change greatly with temperature， which has strong uncertainty. The deterministic aerodynamic design of the rotor for a single atmospheric density may lead to a significant increase in the power consumption of the rotor at off-design points， affecting the normal use of the Mars helicopter. In order to avoid the above problems， this paper first studies of Martian atmospheric environment and establishes the probability distribution model of Martian atmospheric density. For the Mars hexacopter with greater application potential， the viscous vortex particle method is then used to establish a high-confidence refined rotor aerodynamic model in the Martian atmosphere， and the robust design optimization of the rotor aerodynamic shape is carried out by non-dominated sorting genetic algorithm Ⅱ. The designed rotor aerodynamic shape scheme maintains good aerodynamic performance in the face of Mars atmospheric density changes， and has stronger robustness， which is conducive to the Mars hexacopter to perform longer and longer Mars exploration missions in different atmospheric environments.