Abstract: The ultra-low Reynolds number environment of Mars has led to a significant deterioration of the aerodynamic characteristics of the propeller system compared with the Earth environment, and the laminar flow separation phenomenon on the surface of the airfoil affects the aerodynamic characteristics of the Martian propeller. In order to design a propeller suitable for the low Reynolds number environment of Mars, and to deeply study the mechanism effect of ultra-low Reynolds number on the aerodynamic characteristics of airfoils, a numerical simulation method for unsteady compressible N-S equation was proposed based on a Transition SST transfer model, and the aerodynamic characteristics of several airfoils suitable for low Reynolds number environment of Mars were simulated and calculated to select the most suitable airfoil for the Martian atmospheric environment. The results show that the CLF5605 airfoil possesses a better aerodynamic performance. And the aerodynamic characteristics of the selected airfoils were simulated and calculated under different ultra-low Reynolds number to reveal the influence of ultra-low Reynolds number on the aerodynamic characteristics of airfoil, including the range of Reynolds number in the Martian atmosphere and the higher Reynolds number correspond to better aerodynamic performance. And then, the surface boundary layer state of the airfoil was simulated from 100 to 20000 Reynolds number. The results show the significant changes of the laminar flow separation structure of the airfoil, the laminar flow boundary layer state begins to bring laminar flow separation with the increase of Reynolds number, and some laminar flow separation bubbles are generated at the tail edge of the airfoil, becoming turbulent boundary layer. Finally, according to the method of minimum energy loss, a Mars propeller was designed, simulating numerically its aerodynamic performance, carrying out a serious of ground bench experiments to verify for the lightweight propeller, and comparing the ground experimental results with the CFD numerical simulation results to verify the rationality of the lightweight design and the accuracy of numerical calculation.