Abstract: The carbon fiber/polyimide composite rudder was designed. And the PAM-RTM software was used to simulate the resin flow of the rudder during the injection process. The forming die was designed according to the simulation results. The high-temperature resistant carbon fiber/polyimide composite rudder was fabricated via resin transfer molding (RTM) process accordingly and the mechanical properties under bending load were investigated to compare with the 3D finite element analysis (FEA) results. The experimental results show that the carbon fiber/polyimide composite rudder maintains the structural integrity under 150% of the service load. The maximum strain of the metal skeleton is 2 408×10^–6, and the maximum strain of the carbon fiber/polyimide composite skin is 2 371×10^–6. The FEA results reveal that the maximum stress of the metal skeleton appears at the arc transitional region of the rudder shaft root, while the maximum stress of the carbon fiber/polyimide composite skin emerges in the resin junctional area of the gasket outer arc. The initial damage of the carbon fiber/polyimide composite rudder is the transverse tensile failure of the skin unidirectional tape.