The surgical technology of artificial joint replacement has been very mature, but the degree of match between the prosthesis and the human body has a great influence on the surgical effect. At present, most of the prostheses come from Europe and the United States, and their design is in accordance with the standard of Westerners’ body shape, which is quite different from that of the Chinese. And each type of prosthesis is limited, it is difficult to do according to the patient’s bone characteristics “tailor-made”, the conventional practice is to “cut the foot to fit the shoe” in order to get a better match to the skeleton, but there are still some patients can not choose the right prosthesis.CT imaging, The development of CT imaging, computer technology and engineering production technology has given rise to computer-aided design and production of artificial joints customized according to the patient’s own bone morphology. The Department of Orthopaedics of the Ninth People’s Hospital of Shanghai Jiao Tong University (SJTU) and SJTU are the first in China to collaborate in the development and refinement of this technology, which has been successfully applied to hundreds of patients. Firstly, x-ray or CT data are imported into the computer, and a 1:1 ratio model with the lesion site is made by rapid prototyping technology, on which simulated surgery and prosthesis design, and simulated surgical installation are carried out. This method has the advantages of short processing time, good matching with bone, easy installation during surgery, and good postoperative effect. At present, it is mainly used for joint and bone reconstruction surgery for bone and joint tumors, artificial joint revision, severe congenital skeletal developmental abnormalities and other diseases.