Abstract: [Objective] The Dingshan–Dongxi area on the basin margin in southeastern Sichuan is located at the junction of the eastern Sichuan faul–fold zone and the northern Guizhou fault–fold zone on the east side of the Luzhou–Chishui tectonic superposition zone. Affected by multiple tectonic movements, the structure is complex. The Longmaxi Formation in the study area is rich in shale gas resources, with superior geological and reservoir formation conditions, and has great potential for exploration and development. Clarifying the current in-situ stress state and its distribution law is conducive to improving the development efficiency of shale gas. However, the current in-situ stress field in this area is complex, resulting in less precise planar prediction results and significant differences in the fracturing stimulation effect and production between horizontal wells. [Method] This study provides a detailed interpretation of the direction of the in-situ stress in the well profile of the study area, integrating multi-source data including core tests, well logging and microseismic monitoring. Furthermore, the distribution characteristics of in-situ stress magnitudes of the well profile are clarified through hydraulic fracturing, acoustic emission experiments and well logging. The structural deformation and fracture characteristics of the study area were subjected to refined geological modeling and heterogeneous rock mechanics were assigned. Numerical simulation software was applied to simulate the current in-situ stress distribution characteristics of the study area. Finally, based on the analysis of the influence of current in-situ stress characteristics on the effect of fracturing modification, the in-situ stress zoning evaluation standard was constructed. Combined with the simulated results of the in-situ stress field, the in-situ stress zoning was carried out in the Dingshan–Dongxi area, and the zoning outcome was verified through the retrospective evaluation of the fracturing effect of new wells. [Results] The results show that the current in-situ stress direction in the study area is mostly near-EW direction, and local deflection occurs due to the influence of fractures and structural deformations. The maximum horizontal, minimum and vertical horizontal principal stresses range from 58.4–167.0 MPa, 38.6–135.4 MPa, and 54.7–148.2 MPa, respectively, indicating a strike-slip stress state. The differences between maximum and minimum horizontal principal stress mainly distributed between 5 and 30 MPa. The magnitude of in-situ stress and the difference between maximum and minimum horizontal principal stress are generally controlled by the burial depth. The in-situ stress and the difference between maximum and minimum horizontal principal stress both are lower in areas with high structural deformation, while the in-situ stress is lower and the difference between maximum and minimum horizontal principal stress is higher near faults. The zoning is carried out with a minimum horizontal principal stress of 80 MPa and a difference between maximum and minimum horizontal principal stress of 20 MPa. It is recommended to select the areas with low stress difference and low in-situ stress to conduct fracturing stimulation. These areas are mainly located in the high structural parts of the gentle slope area in the middle of Dingshan, the slope area of Dongxi, and the northern part of the Dongxi fault and anticline area. [Significance] This study advances the understanding of the current in-situ stress field of the Longmaxi Formation in the southeastern margin of the Sichuan Basin and possesses significant practical value for the optimization of fracturing stimulation.