The invention relates to a 3D intelligent modeling method and system and a flexible manufacturing system of a 3D model. A single photograph or picture is converted into a 2D shadow picture; after a 3D model is constructed, the information of the 2D shadow picture is hidden in the 3D model, a shadow presented by the 3D model with the hidden information of the 2D shadow picture through illumination angle projection is in an original picture or photograph shape, and 3D intelligent modeling can be realized by methods, such as accumulation, splicing, stretching, extrusion and the like. The flexible manufacturing system of the 3D model enables a user to integrally experience the processes of 3D modeling and 3D printing, 3D modeling compatible data is created, stored, transmitted and managed for a user, and the user is guaranteed to carry out 3D printing at any time and place so as to realize the flexible manufacture of the 3D model.