Ammonium perchlorate (AP) is an important oxidant in solid propellants, and its thermal decomposition performance directly affects the combustion characteristics of solid propellants. The use of combustion catalysts can lower the decomposition temperature and increase the decomposition rate of AP. Different methods for microstructure control of nano-combustion catalysts for AP thermal decomposition were studied and summarized. The effects of microstructure control methods such as crystal planes, defects, and composite interfaces on the catalytic activity and catalytic mechanism of combustion catalysts for AP thermal decomposition reaction were analyzed. Besides, the characteristics of catalysts that can achieve optimal catalytic performance were explored. The results indicate that the catalytic activity of nanometal oxide combustion catalysts can be improved by adjusting the exposed crystal faces, element doping and constructing a composite interface structure. Among them, transition metal oxide nano-catalysts can enhance catalytic activity by exposing designated crystal planes, and element doping enhances catalytic activity by generating defects, while constructing a composite interface structure utilizes interface effects to regulate the activity of catalytic sites, thereby enhancing catalytic activity. Transition metal oxide nano-catalysts showed good catalytic activity in improving the thermal decomposition performance of AP.