Abstract: The delignified wood(DW) was impregnated by methyl methacrylate(MMA) to obtain lignin-removed wood/poly(methyl methacrylate)(DW/PMMA) composite material through in-situ polymerization. The properties of DW/PMMA composite materials were investigated. The results showed that the removal ratio of different lignin had a greater impact on the properties of wood, and the impact was more significant with the increasing removal ratio of lignin. The density of DW/PMMA composite was significantly higher than that of non-impregnated wood. Especially when the lignin removal ratio reached a high level(H-DW), the density of the composite material could reach 1.15 g/cm³, which was close to that of pure PMMA. Compared with DW, DW/PMMA had lower volumetric moisture absorption and water absorption expansion coefficient, and incremental volumetric expansion resistance, which indicated that the impregnation of MMA effectively improved the dimensional stability of DW. The DW/PMMA exhibited better mechanical property than that of the untreated wood/PMMA. Dynamic thermomechanical thermal analysis showed that the filling of PMMA effectively increased the rigidity of the prepared composite material.The DW/PMMA composites prepared in this study had excellent dimensional stability and mechanical properties. Among them, the bending strength of L-DW/PMMA impregnated with low lignin removal rate wood(L-DW) was 122.6 MPa, the bending modulus was 10 302.41 MPa, and the compression modulus was 5 492.14 MPa, which was more excellent than that of the untreated wood/PMMA.