In the early stage of body development, it is crucial to quickly and automatically generate a high-maturity body-in-white (BIW) model. This paper takes the solution for the side panel as an example, based on modeling requirements and the design association of the side panel model, it extracts the styling and general layout features related to the side panel, collects typical sections, establishes a typical section feature library, and also develops an interface program between sections and EXCEL spreadsheets, realizing the driving of key design elements on the side panel structure. Based on the modeling strategy of the intermediate layer, the knowledge engineering method is adopted to encapsulate basic modeling operations into forms such as user-defined features and the secondary development program based on CATIA component application (CAA). A parametric template is established, which realizes automated parameter iteration in the early stage of design, and also achieves standardization of the modeling process, ensuring the reliability of the side frame model.