The Weiyuan area is located in the southwest of the Sichuan basin. Its main structure, the Weiyuan anticline, is a large dome-shaped anticline and has experienced the superimposed deformation by multiple tectonic movements. The previous understanding of the formation process and mechanism of the Weiyuan anticline is controversial, which cannot meet the needs of fine exploration and efficient development of oil and gas. In this paper, through the structural analysis of seismic data, it is determined that the main body of the Weiyuan anticline was formed under the condition of basement pre-existing structure (NE-trending basement paleo-uplift) in the process of nearly NS oblique compression in Yanshan epoch, and the nearly NS oblique compression in Himalayan epoch also contributed to its structural deformation. According to this understanding, the sandbox modeling experiment was designed, and the experimental results well reproduced the structural characteristics of the Weiyuan anticline on the plane and profile, indicating the rationality of the above understanding. These understandings can not only guide the exploration and development of oil and gas in the Weiyuan gas field but also provide a reference for the formation and evolution mechanism analysis in similar areas.