Abstract: In this paper, octaaminopropyl POSS(OA−POSS) and DOPO derivatives(DPA) were synthesized, and then DOPO, DPA and OA−POSS were introduced into WF/PP wood-plastic composites. The flame-retardant WF/PP wood-plastic composites were prepared by the hot pressing method, and the thermal decomposition, combustion properties and mechanical properties of the flame-retardant wood-plastic composites were explored. Thermogravimetric(TG) analysis shows that the addition of DOPO, DPA and OA−POSS increase the initial thermal decomposition temperature of the composites to a certain extent, reduce the thermal decomposition rate, and significantly improve the quality of the pyrolysis residue of the material. The cone calorimeter(CONE) test shows that the addition of DOPO, DPA and OA−POSS can significantly improve the flame retardant properties of composites. The carbon residue of the composite material increased significantly, with a maximum increase of 228.05%. The addition of DOPO decreases the mechanical properties of the material, while the addition of DPA and OA−POSS can enhance the mechanical properties of the composites.