Stiffened composite panels are widely used in aircraft structures due to their excellent load-bearing capacity. This paper conducts an analysis on the load-bearing issues of hat-shape composite panels. Through typical domestic T800 stiffened composite panel compression failure tests, the compressive buckling load was found to be approximately 500 kN, and the failure load was 850 kN, demonstrating strong post-buckling strength. Therefore, fully utilizing the post-buckling characteristics of the stiffened panel can effectively improve the material utilization efficiency. Subsequently, a quasi-static method was adopted to conduct nonlinear simulation analysis of the stiffened panel from loading until failure, resulting in a calculated failure load of 786.4 kN, with a deviation of − 7.48% compared to the experimental value. Then, the residual load-bearing performance of damaged stiffened composite panel was analyzed, with a simulation result of 355.7 kN.