Abstract: Small progress has been made in the exploration and development of shale gas in the Lower Cambrian Qiongzhusi Formation over the years. The high-yield gas flow in Well Zi 201 has greatly increased confidence in the large-scale and commercial development of shale gas in Qiongzhusi Formation. The different enrichment laws in various areas and layers and the optimal selection of favorable areas are the primary problems to be solved for shale gas development. Based on the analysis of paleontology, sedimentary facies, and reservoirs in 57 wells in Sichuan Basin, the theoretical basis for the deployment of Well Zi 201 and enrichment conditions of shale gas in Qiongzhusi Formation are analyzed in detail, and the exploration and development orientation are pointed out. Firstly, a stratification standard for Qiongzhusi Formation is established. It is clarified that four sets of organic rich shale of deep shelf facies were developed in Qiongzhusi Formation (layers ①, ②, ③, and ④), which were controlled by the development of rift troughs, with the largest shale thickness in the trough. The characteristics of shale reservoirs are analyzed, which indicate that the reservoir pressure, porosity, and gas saturation show an increasing trend from bottom to top, and from the outside to the inside of the rift trough, and reservoir overpressure plays an important role in the preservation of shale pores. On this basis, an overpressure and differential shale gas enrichment mode of “different facies in multiple layers and overpressure pore preservation” in Qiongzhusi Formation has been established, and it is pointed out that the overpressure pore development area (interval) far away from the dispersion pathway is the favorable area (interval) for shale gas enrichment. Finally, the study results indicate that Well Zi 201 and its surrounding areas are the main areas for increasing shale gas reserves and production in the future, with resources of 8.06×10¹²m³. It shows considerable development potential in western Sichuan Basin, with resources of 0.72×10¹²m³. Affected by graphitization and tectonic activities, areas with overpressure pore development far from weathered crust and surface outcrops are favorable for shale gas exploration in Changning in southern Sichuan Basin and northern Guizhou Province.