Abstract: In traditional 3D process design, the construction of process models relies heavily on manual modeling, which has problems such as low efficiency and poor model consistency, affecting the quality and efficiency of process design. To address this pain point, this paper proposes an automatic generation method of process models based on feature association and intelligent reasoning. This method constructs a complete process knowledge chain through feature recognition, processing reasoning, and intelligent arrangement of process flows, realizing the “one-click” generation and update of process models. The system supports automatic PMI annotation, intelligent association of process resources and parameters, and structured filling of process descriptions, reducing manual errors. This paper elaborates on the business logic, technical architecture, core algorithms and implementation process of the method, and verifies its effectiveness in improving design efficiency and ensuring model consistency through engineering examples, providing a feasible technical path for the intelligent upgrading of 3D structured process design and having reference value for the digital transformation of process design.