This paper comes up with a new general-purpose approach to integrating algorithm modules in all kinds of CAD software applications. In algorithm module integration of mechanical engineering areas, the new approach uses round-robin calculation of algorithm modules instead of traditional hard-coding or specialized configuring methods. Drawbacks of traditional algorithm module integration approach are analyzed in detail, and then the new approach is put forward and discussed accordingly. Using the new approach in CAD software applications, engineering fields can reinforce reusability of algorithm modules; implement parallel calculating of algorithm modules, and increase flexibility of algorithm module integration in engineering tasks. Most of all, it can improve engineers’ work and raise their efficiency.