Abstract: At the end of 2020, Well HY1, the first shale gas risk exploratory well in Jiannan block of Hongxing area, eastern Sichuan Basin, deployed and implemented for Member 2 of the Upper Permian Wujiaping Formation, obtained a natural gas production of 8.9×10⁴m³/d in the fracturing test stage, achieving a major breakthrough in the exploration of shale gas in the Permian in China. Comprehensively based on the exploration results as well as the core, drilling, well logging, well log, X-ray diffraction whole-rock mineral analysis, and carbon isotope of Well HY1, the paper systematically analyzes the geological characteristics and main enrichment-controlling factors of Permian shale gas in Hongxing area. Two sets of deep-water shelf subfacies shale are developed in the Permian in Hongxing area, which are characterized by thin high-quality shale, high abundance of organic matters, high porosity, high gas content and high content of brittle minerals. The widely developed deep-water shelf subfacies shale is the material basis for the enrichment of Permian shale gas. The organic-inorganic synergism provides good reservoir space and high adsorption capacity. Good preservation conditions are the key to the enrichment of shale gas in Hongxing area. The breakthrough in exploration of Well HY1 demonstrates as below. (1) The Permian shale gas in southern China has a good exploration prospect and is a key field for increasing reserves and production. (2) The relatively weak deformation area in the complex tectonic area outside the basin indicates an important direction for shale gas exploration. (3) The integration of geological engineering is an important guarantee for the breakthrough in Permian shale gas exploration. (4) The modification technology of thin reservoir and ultra-deep shale and the production and transportation technology of acid shale gas reservoir are the key to a breakthrough in the large-scale high-efficiency development of Permian shale gas. The research and understanding have great reference and guiding significance for the exploration and development of shale gas reservoirs with similar geological backgrounds.