Abstract: An approach of intelligent fitting model of emotional modeling primitives is proposed to solve the limitations of the traditional product design methods that are difficult to carry out the overall design and the interference between the appearance design and the mechanical structure design. By using the principle of visual perception to analyze consumer needs, the principle of visual perception is determined as an effective way to connect perceptual psychology and modeling elements. Combining with extension theory, a method for generating modeling elements based on emotional images is given. Analyzing the influence of product mechanical structure on appearance modeling, and combining extension transformation ideas and parametric design software, a modeling fitting concept is proposed, a product modeling method system is constructed based on user emotional collaborative structural design, and new ideas for product modeling design provided. Finally, the feasibility of the method is verified through an example of trocar.