In order to solve the problem of improving the matching degree between the designed clothing and the user’s body shape, the author proposes an interactive clothing optimization design model based on 3D printing. The user logs in to the system through the user layer, and the display layer uses 3D scanning technology to scan the human head, torso, and other information to collect human body data, and project the collected human body data to obtain the human body outline, select the human body contour line obtained by the denoising process of the interpolation algorithm, extract the feature points of the human body contour line after the denoising process through the corner point detection method, and use the final feature points to obtain the final contour line, the 3D human body data file is generated and sent to the interface layer, the interface layer designs clothing through style design, adding colors and patterns, and uses the global optimization method to adaptively adjust the clothing pieces to achieve clothing design, fit the designed clothing through the virtual fitting module until it meets the user’s needs. Experimental results show that: The system collects user size with an accuracy of higher than 99.5%, and the number of iterations for adaptive adjustment of human body size is less than 30 times. Conclusion: The designed clothing virtual design system can effectively make up for the blank of clothing e-commerce, with high innovation and high practicability.