Abstract: In the traditional teaching mode of mechanical engineering, teachers try to explain the difficult concept ofcomplex shape parts and mechanism to students, teaching and two-dimensional illustrations cannot be effectively helped students understand. Although the physical teaching aids are vivid and straightforward, but they are very expensive to buy the specific models for special issues, and they are not convenient to be promoted. 3D printing technology can shorten the production cycle and be used easily. Those teachers who do not have the professional knowledge will be met their demands after using the corresponding teaching aids. To address this problem, the study uses 3D printing technology to design and produceteaching aids.The study also gives the basic theory and operation of processes. Practice has shown that the use of 3D printing teaching models greatly facilitate teachers to explain the complex concept.