1. A method for manufacturing an artificial implant, comprising the following steps: acquiring a pre-operation three dimensional volume image, the pre-operation three dimensional volume image defining an original appearance of a target at an operation portion before incision; acquiring a post-operation three dimensional volume image, the post-operation three dimensional volume image defining a post-operation appearance of the target at the operation portion after incision, the post-operation appearance having at least one incised part on the target comparing with the original appearance of the target; acquiring a pre-operation target image from the pre-operation three dimensional volume image, the pre-operation target image defining a three dimensional volume image of the target before incision; acquiring a post-operation target image from the post-operation three dimensional volume image, the post-operation target image defining a three dimensional volume image of the target after incision; aligning the pre-operation target image with the post-operation target image and generating an aligned image; retrieving a difference image from the aligned image corresponding to the incised part of the target, which is the difference in the pre-operation target image and the post-operation target image; building a three dimensional model of mold points of the incised part based on the difference image; and manufacturing an artificial implant having substantially the same profile as the incised part based on the three dimensional model of mold points.