In this study, an innovative integrated thermal protection system (ITPS) concept that incorporates shaped-stabilized composite phase change material into corrugated core ITPS structure is proposed to strengthen the thermal protection performance. First, the heat transfer characteristics were investigated through both the heat insulation experiment and numerical transient heat transfer analysis. Then, the load bearing capacity is researched through the sequential thermal-mechanical coupling method. Finally, based on the established numerical analysis models, a global optimization procedure was established to verify the advantages of the proposed structure under the actual reentry conditions. Experimental and simulation results show agreement with each other on the thermal insulation ability. And a reduction of 18.46% in maximum bottom face sheet temperature was observed in the experiments when compared with the traditional ITPS. Moreover, the optimization results showed that the proposed ITPS achieved a reduction of 14.32% in weight and a decrease of 46.09% in thickness with respect to the traditional ITPS, which thereby contributes to the lightweight and high structural efficiency of the vehicle design.