The Dabashan foreland fold- thrust belt, located in the transitional position between the Qinling orogenic belt and the Sichuan basin, is an important distribution area for the proven reserves of large and medium- sized oil and gas reservoirs in the Sichuan basin. The research area is located in the Dabashan tectonic belt in the northeastern part of the Sichuan basin, which is characterized by the presence of multiple detachment layers. The distribution of these detachment layers plays a significant role in controlling the structural deformation of the research area. Previous studies have determined the main structural styles of the study area based on geological outcrop data, 3D seismic data, and other technical methods. However, there is still a lack of quantitative analysis of the structural deformation process and kinematic characteristics. To address this gap, our study uses the discrete element numerical simulation method to calculate the differences in structural styles displayed within the same time step using PFC2D software. Three models, namely the single detachment layer system, the dual detachment layer system, and the multiple detachment layer system, were designed for discrete element single factor comparative simulation experiments to explore the differences in structural styles among each detachment layer system. Our experimental results demonstrate the following findings: ① the detachment layer plays a controlling role in the development of structures in the cross section. The dual detachment layer system and the multi detachment layer system exhibit a higher number of faults compared to the single detachment layer system. The introduction of detachment layers adds complexity to the structural development. Additionally, the analysis of the developed fault properties reveals that with an increase in the number of detachment layers, the number of forward thrust faults gradually rises. The number of reverse thrust faults in the multi detachment layer system is less than the first two models and is significantly less than the number of reverse thrust faults in the dual detachment layer system. The middle detachment layer inhibits the formation of reverse thrust faults. ② The introduction of detachment layers accelerates the vertical thrust velocity of faults. The middle detachment layer acts as a connection between the basement detachment layer and the upper detachment layer. The dual detachment layer system commonly exhibits structural decoupling, while the development of secondary faults and folds is the main feature in multi detachment layer systems. ③ The multi detachment layer system shows obvious characteristics of secondary folds and faults, which is more consistent with the profile of the eastern Dabashan. On the other hand, the dual detachment layer system exhibits more structural decoupling characteristics, which corresponds to the profile of the western section.