CBR (Case-based reasoning) technique is increasingly applied in the process planning and dies intelligent design for stamping parts. In these applications, stamping parts information acts as the problem domain of cases model, while stamping process and die information as the answer domain. The similarity computation and retrieval of stamping parts are essential to the case-based design of stamping process planning and dies. In this paper, that issue is studied targeting automotive panel as the research object, and a retrieval method for similar panel parts based on the automobile panel coding is proposed. The coding structure is designed considering the automobile panel's features, especially the geometry shape features and their relationship. And the corresponding similarity calculation method is put forward. Finally, a case study is used to reveal the effectiveness of this methodology.