Universal joint torque tube assembly is used in flaperon transmission system of high lift system. As an important part of aircraft, its performance determines the main function and fatigue life of aircraft. Wear between components seriously affects the transmission accuracy of universal joint. This paper takes the cross-shaft universal joint as the research object, uses the liquid metal friction and wear testing machine to measure the wear coefficient of the cross-shaft universal joint material. A numerical simulation model for friction and wear was established based on the Archard wear model, and compared with friction and wear tests. Subsequently, a validated numerical simulation model was used to study the friction and wear problem of the cross shaft universal joint. A model for analyzing the wear clearance angle of the cross shaft universal joint was proposed. Based on the analysis results and Archard wear theory, optimization suggestions were proposed to increase the hardness of the universal joint ear piece, and a comparison was made with the original structure"s full life wear clearance angle. The research results indicate that the numerical simulation results based on the Archard wear model have good consistency with the experimental results, and the numerical simulation results can predict the wear results well, thereby significantly shortening the test cycle and increasing design efficiency. Increasing the hardness of the universal joint ear can effectively reduce the wear clearance angle of the cross shaft universal joint. At 25 ℃, the full life wear clearance angle is relatively reduced by 24.5%, and at 400 ℃, the full life wear clearance angle is relatively reduced by 20.6%. The research results provide certain guiding value for the anti-wear design of universal joints.