Abstract: The flexural performance of carbon fiber reinforced polymer sandwich structures with aramid honeycomb cores is significantly governed by the coupled effects of multiple parameters, including face sheet thickness, core thickness and core orientation. In this paper, the influences of the above parameters on the bending behavior and progressive damage failure mechanism of the sandwich structures are systematically investigated via three-point bending tests and finite element simulations. The results indicate that core thickness exerts a remarkable effect on the ultimate load-bearing capacity and progressive damage evolution of the structure. Core orientation plays a dominant role in structural load-bearing capacity, the failure load of structures with L-oriented cores is nearly 80% higher than that of structures with W-oriented cores. Face sheet thickness also produces a significant impact on the load-bearing capacity. This study reveals the progressive damage evolution mechanism of aramid honeycomb sandwich structures under the coupling of multiple parameters, and provides essential fundamental support for the refined design of such structures.