A 3D printing method, applied to a 3D printing apparatus, the 3D printing apparatus comprises a container (11, 21) and a component platform (12, 22), the container (11, 21) is used for containing a photocurable material, wherein, the 3D printing method comprises the following steps: adjusting a spacing between the component platform (12, 22) and a preset reference printing-surface to fill the photocurable material to be cured; curing the photocurable material filled within the spacing into a corresponding patterned cured layer according to a layered image in a tooth model; and repeating the above steps to form a tooth structure on the component platform (12, 22) through accumulation of patterned cured layers, wherein the tooth structure comprises a tooth portion and a tooth holder portion used for supporting the tooth portion; wherein, during a process of printing the tooth structure, a thickness of at least one patterned cured layer for forming the tooth portion is less than a thickness of at least one patterned cured layer for forming the tooth holder portion, wherein the layered image in the tooth model is described in corresponding cross-sectional layer which is obtained by a method for layering three-dimensional object data, which comprises: layering the tooth model to obtain cross-sectional layers forming the tooth model, wherein a layered image of the tooth model at corresponding layer is described in each cross-sectional layer; wherein, during the layering, a thickness of at least one cross-sectional layer in the tooth portion model is set to be less than a thickness of at least one cross-sectional layer in the tooth holder portion model, characterized in that the method for layering three-dimensional object data further comprises: identifying tooth feature information and support feature information in each layered image described in at least partial cross-sectional layers, and determining an intersecting cross-sectional layer between the tooth portion model and the tooth holder portion model based on an identification result. adjusting a spacing between the component platform (12, 22) and a preset reference printing-surface to fill the photocurable material to be cured; curing the photocurable material filled within the spacing into a corresponding patterned cured layer according to a layered image in a tooth model; and repeating the above steps to form a tooth structure on the component platform (12, 22) through accumulation of patterned cured layers, wherein the tooth structure comprises a tooth portion and a tooth holder portion used for supporting the tooth portion; wherein, during a process of printing the tooth structure, a thickness of at least one patterned cured layer for forming the tooth portion is less than a thickness of at least one patterned cured layer for forming the tooth holder portion, wherein the layered image in the tooth model is described in corresponding cross-sectional layer which is obtained by a method for layering three-dimensional object data, which comprises: layering the tooth model to obtain cross-sectional layers forming the tooth model, wherein a layered image of the tooth model at corresponding layer is described in each cross-sectional layer; wherein, during the layering, a thickness of at least one cross-sectional layer in the tooth portion model is set to be less than a thickness of at least one cross-sectional layer in the tooth holder portion model, characterized in that the method for layering three-dimensional object data further comprises: identifying tooth feature information and support feature information in each layered image described in at least partial cross-sectional layers, and determining an intersecting cross-sectional layer between the tooth portion model and the tooth holder portion model based on an identification result. layering the tooth model to obtain cross-sectional layers forming the tooth model, wherein a layered image of the tooth model at corresponding layer is described in each cross-sectional layer; wherein, during the layering, a thickness of at least one cross-sectional layer in the tooth portion model is set to be less than a thickness of at least one cross-sectional layer in the tooth holder portion model, characterized in that the method for layering three-dimensional object data further comprises: identifying tooth feature information and support feature information in each layered image described in at least partial cross-sectional layers, and determining an intersecting cross-sectional layer between the tooth portion model and the tooth holder portion model based on an identification result.