Project teaching is a question-oriented teaching mode. Teaching project design is a key section of project-based teaching. This paper discussed the problems existing in the teaching of mechanical optimization design. According to the characteristic of the course, project teaching can improve teaching quality. On the basis of the student’s enhancement on the application of the theory, a real example of belt and chain drives optimization problem is selected as a teaching project. It is established the optimal design model including objective function, constraints etc. The optimal design model is solved through chart data, model realization and reconciliation by using Microsoft Excel. In this way, it has the advantages of simple modeling process, high speed of optimization design, high readability of design data and high level of design automation and so on. So it can save a lot of time and make the design process more convenient. This project can achieve the teaching-learning-doing combination and cultivation of students’ application ability. Teaching practice shows that the project-oriented teaching can raise the interests of students in learning and the ability to solve practical problems.