In view of designing experience and customization demand for the consumer, the man-machine interaction technology is applied in industrial product design and system development. With involute spur gears as a research example, parametric interaction design interface of gear product is developed which utilizing feature modeling, parametric function and secondary development technique of CREO tool. In the Visual Studio compile environment, can not only realized the editing, modification and reconstruction of the gear’s geometry model conveniently and quickly, but also improve the design efficiency and plasticity of the gear product. Through implement process exploring of the gear product’s operational mode of man-machine interaction, the key technology of secondary development on CREO platform is proved, thus then some important reference and support are provided for interaction design of industrial product.