A partition design and molding method for an acetabular cup prosthesis with a porous surface includes the following: modeling of a spherical shell of an acetabular cup; cutting of the spherical shell of the acetabular cup into equal parts; integrated design on a porous layer of a surface of the partitioned acetabular cup prosthesis; reorganization of the partitioned acetabular cup prosthesis; construction of a hemispherical acetabular cup prosthesis; and 3D printing and manufacturing of the acetabular cup prosthesis. Through the disclosure, the formed porous layer is perpendicular to the surface of the acetabular cup, so favorable mechanical properties are provided. A fully interconnected branch-rod structure is provided, and there is no isolated rod, so that inflammation or even re-revision led by the detachment of isolated rods during long-term postoperative activities is prevented.