Abstract: Based on the high-temperature aerodynamic load environment of aero-engines, the high temperature resistant TG800 carbon fiber/polyimide resin composite cylindrical casing test piece, which with flanges for installation and window openings on the casing wall, prepared by the resin transfer molding (RTM) process was carried out simulation analysis and load-bearing performance test under room temperature, 200℃ and 260℃ high-temperature aerodynamic load. The simulation results show that the high stress level of the composite casing occurs at the installation flange and the window of the shell wall. In the load-bearing test, the designed special test device and the composite casing test piece are combined to form a test chamber structure that can decouple the internal pressure and the axial force during loading. By applying high-temperature gas pressure and mechanical static load to the designed special test cavity to simulate the high-temperature aerodynamic load of the aero-engine, compared with the traditional pressurization method of stamping capsule, it can achieve more realistic assessment of the casing flange and window. The non-destructive testing on the window of the casing after the load-bearing test at room temperature, 200℃ and 260℃ shows that the delamination damage area at the window expands towards a larger square and circular shape as the load increases. The failure mode of the TG800 carbon fiber/polyimide resin composite casing obtained by the 260℃ destruction test is installation flanging fracture, which is different from the failure mode of the traditional metal casing cylinder rupture. The results indicate that the mechanical properties of TG800 carbon fiber/polyimide resin composite structural components prepared by RTM process have good temperature stability within 200℃. The installation flanging is the weak area of the composite casing under the high temperature aerodynamic load of the aero engine, which is an important optimization part for the weight reduction design of the casing.