In this study, the absolutely recycled plastic wood (ARCPW) was fabricated with post-consumer high density polyethylene (HDPE) and wood flour from the saw mills. The alkaline, silane and maleic anhydride modified polypropylene (MAPP) were used as modifiers to treat wood fiber and improve the interfacial adhesion of ARCPW. Effects of wood fiber length, weight fraction and surface treatment on the mechanical properties of ARCPW were investigated. The flexural fracture surfaces of ARCPW were examined and the fracture mechanism of ARCPW was also analyzed in this paper. The results indicated that ARCPW with wood fiber simultaneously treated by alkaline, silane and MAPP possesses the best mechanical properties. The higher the content of wood fiber, the better the flexural strength of ARPCW. The interfacial adhesion of prepared ARCPW is ideal and a good compatibility between wood fiber and matrix was obtained.