The synergistic effect of calcium-zinc stabilizers and foaming agents serves as a dual guarantee for WPC door panel quality. Environmentally friendly calcium-zinc stabilizers can accurately match the decomposition temperature of foaming agents, stabilize the decomposition rate, avoid problems such as cell collapse and sparseness, and help form a uniform and dense cell structure, significantly improving the sound insulation, thermal insulation performance, and structural stability of door panels. Meanwhile, their excellent thermal stability can adapt to the entire high-temperature process of processing, inhibit the thermal decomposition of PVC resin, eliminate defects such as internal cracking, surface carbonization, and yellowing of door panels, and balance appearance texture with internal strength. The combination of the two also complies with environmental standards for building materials, helping enterprises avoid environmental inspection risks from the source and achieve a product balance between lightweight and high rigidity.