The definition and functions of parametric design were introduced.According to the practical condition of mechanical engineering design,the necessity and feasibility of parametric design for complex mechanical engineering design was analyzed.The related key technologies and methods were also discussed by a project example based on Inventor platform. The definition and functions of parametric design were introduced. According to the practical condition of mechanical engineering design, the necessity and feasibility of parametric design for complex mechanical engineering design was analyzed. The related key technologies and methods were also discussed by a project example based on Inventor platform.