The invention relates to the field of wood mold casting, in particular to a method for improving the plane smooth degree of a wood mold. The method comprises the following steps that 1, the mold is designed, wherein software is used for designing a wood mold structure, the size of all plane portions of the wood mold is reduced by 1 mm, and all the plane portions are used for installing aluminum plates; 2, the mold is manufactured, wherein according to the wood mold structure, wood is used for machining and manufacturing the mold; 3, the aluminum plates are bonded, wherein a plate shearing machine is used for shearing the aluminum plates, and the aluminum plates are bonded to all the planes of the wood mold; 4, the edges of the aluminum plates are reinforced, wherein the edge portions of the aluminum plates are reinforced by riveting rivets, and cracking is prevented; and 5 the surface of the mold is treated, wherein the connecting portions of the aluminum plates and other faces are sanded and polished. By installing the aluminum plates on all the surfaces of the wood mold, the wood mold plane smooth degree is improved, the situation that due to the fact that sand adheres to the wood mold, the wood mold is damaged is prevented, drawing performance of the wood mold can be reinforced, the surface quality of sand cores is improved, few mold releasing agents are used, manual operation time can be shortened, and the working efficiency is improved.