Wood is favored by furniture and decorative materials due to its beautiful color and texture, lightweight and high strength, but the thermal stability and flame retardants of wood have not been well solved. In this paper, metal salt-doped ammonium polyphosphate silicon gel (Cu, Mn/APP/Gel) was trapped in the wood cell wall and cell cavity by vacuum-pressure infusion method and vacuum drying method. Compared with unmodified wood, Cu, Mn/APP/Gel impregnated wood can rapidly enhance the flame retardant and smoke suppression capability of wood due to the catalysis of Cu2+ and Mn2+, and the total h...