Composite solid propellant often needs to add solid catalysts to improve its combustion performance, but result in the reduced mechanical properties. According to the situation, a novel research strategy was proposed, which ammonium perchlorate (AP) was packed into the layered porous structure of copper alginate (Cu-A). Cu-A effectively enhances the interfacial interaction between AP and binder matrix by reacting with toluene diisocynate. In addition, Cu, Cu 2O and CuO produced by the decomposition of Cu-A are well dispersed in carbonated porous framework decomposed by Cu-A with electrical conductivity, which realizes the efficient catalysis for AP. After being applied to AP-based propellant, AP/Cu-A strengthens its ignition capacity and combustion rate, which organic porous structure of Cu-A plays a role in combustion-supporting effect. The tensile results show the maximum tensile strength of the propellant is increased with the reduced adhesion index. It confirms the enhanced interface force between AP and binder matrix by Cu-A, which alleviates the dewetting phenomenon. It is clearly that AP/Cu-A improves the negative effect of solid combustion catalysts on the mechanical performance of prepared propellant, which has both excellent combustion and mechanical properties. The study offers a new perspective for the selection of combustion catalysts for the propellant.