Based on selective laser sintering of rapid prototyping process, the composites were prepared by filling PES with wood flour. For enhancing the affinity of high polar wood flour and non polar PES, and improving the bonding strength, the wood flour was modified via alkalinization. This paper studied the effects of adding compatibilizer and alkaline treatment on the forming accuracy and mechanical property of WPC. The test results show alkaline treatment decreased the hydrophilicity of wood flour, increased the contact area between PES and wood flour and improved the bonding strength. Adding the compatibilizer polypropylene grafting maleic anhydride (PP-g-MAH) can form bonds between the wood flour PES and PP which improves their compatibility and mechanical property more. After performance testing, the relative warping rate is only 0.26%, the tensile strength is 0.014MPa, and shock strength is 0.954KJ/m2.