The feasibility of preparation process for composite material arm of Air-Cushion Vessel (ACV) duct is analyzed, the combinational design scheme of duct arm sample materials is optimized, and the. mixed fiber epoxy resin composite material-foam sandwich is selected as the duct arm material. Considered the economy and operability of duct arm structure manufacturing, the integral molding mode is selected, Vacuum Infusion Molding Process (VIMP) is used to make the preparation for duct arm sample, and the mechanical property test of duct arm structure is conducted. The test results show that the designed ACV duct arm sample meets the use requirements of strength and stiffness, which can provide reference for the subsequent lightweight and low-cost design of duct structure.