The third member of Xujiahe Formation in the Western Sichuan Depression belongs to low porosity and low permeability-ultra-low porosity and ultra-low permeability tight reservoirs, which have great exploration potential for finding gas within the source. Based on the distribution of oil and gas, the geological background of accumulation in the target area, and the dissection of key wells and high-quality source rocks, combined with previous achievements, the characteristics of source rocks and sedimentary facies in the Xiaoquan-Fenggu structural belt, spatial distribution, oil and gas evolution process, and pressure system research, the main controlling factors of accumulation in the Xiaoquan-Fenggu structural belt were analyzed, and it is clarified that this area is a vertical superposition-plane interweaving-close superposition migration and accumulation mode, In-source accumulation is the gas accumulation type of delta front subfacies. It is concluded that the main controlling factors for accumulation in the study area are the development of high-quality source rocks, the development of favorable facies belts, the formation and maintenance of abnormal pressure.