Abstract: High-altitude environments are characterized by low atmospheric pressure and thin air, which exert significant impacts on the performance of the fuel supply system of aviation piston engines. This paper deeply investigates the influence mechanism of high-altitude conditions on the fuel supply system. Targeted optimization measures are proposed based on theoretical analysis and data statistics, and the effectiveness of the optimized scheme is verified via simulation experiments. The research aims to improve the reliability and fuel economy of the engine operating under high-altitude environments.