A layering method for three-dimensional object data, and a 3D printing method and device. The 3D printing method is applied to the 3D printing device. The 3D printing device comprises a container for containing photo-curing materials and a component platform. The 3D printing method comprises: adjusting a spacing between the component platform and a preset printing datum plane to be filled with the photo-curing materials to be cured; curing the photo-curing materials in the spacing into a corresponding pattern curing layer according to layering images in a tooth model; and repeatedly executing the steps to form a tooth structure formed by the pattern curing layers in accumulation fashion on the component platform, wherein the tooth structure comprises a tooth part and a tooth base part used for supporting the tooth part, and in the process of printing the tooth structure, the thickness of at least one pattern curing layer for forming the tooth part is smaller than that of at least one pattern curing layer for forming the tooth base part.