Abstract: Recently, breakthroughs have been made in the field of Permian fault controlled oil and gas reservoirs in the Qijiang area of southeastern Sichuan. However, the development characteristics of fault systems and their control over reservoir formation and oil and gas enrichment are still unclear. Based on seismic, drilling, logging, core, and various analysis and testing data, through fine analysis of the fault system and reservoir development characteristics, gas source comparison, reservoir formation stages and processes in the Lizi exploration area, the differences in reservoir formation and formation processes under fault control are clarified. The results indicate that the Lizi exploration area has developed NNW and NE trending thrust slip faults during the Yanshan Himalayan period, but deep NNW trending faults exhibited right lateral strike slip characteristics during the Caledonian Hercynian period. During the Haixi period, the NNW trending strike slip fault had high vertical activity intensity, which was conducive to the backflow and infiltration of surface fluids along the fault zone, forming karst/dolomitized reservoirs. During the Yanshan period, under the background of basin margin compression, pre-existing strike slip faults along the NNW direction formed fault propagation folds, accompanied by structural fracture cave systems that improved the original pore permeability properties of the reservoir. Comparison of gas sources shows that the NNW trending fault gas reservoir is supplied with mixed hydrocarbons from the Longmaxi Formation and Maoyi Member, while the NE trending fault gas reservoir is mainly supplied with hydrocarbons from Maoyi Member. The NNW fault experienced three stages of oil and gas accumulation, namely the early Late Permian, late Late Permian, and Middle Jurassic. The process of oil and gas accumulation occurred in the Late Permian, when the source rocks of Longmaxi Formation entered the peak of oil generation, generating crude oil that entered the Maokou Formation reservoir along the NNW trending fault to form an ancient oil reservoir; During the Indosinian period, the source rocks of the Maoyi Formation entered the peak of oil generation, generating crude oil that entered the Maokou Formation reservoir along NNW and NE trending faults; Since the Yanshanian period, two sets of source rocks have entered a peak of gas generation, and the superimposed ancient oil reservoirs have undergone cracking and gas generation, ultimately leading to the adjustment and formation of oil and gas reservoirs.