Abstract: Shale gas resource is abundant and has a broad development prospects in China, but the quality of shale gas resources in China is different from that in the United States. China must develop its own development techniques. For this purpose, based on independent innovation, China National Petroleum Corporation (CNPC)has carried out systematic theoretical and technical research on the geological and engineering characteristics of Longmaxi Formation shale gas in the southern Sichuan Basin. Guided by "three-factor controlling" theory, i.e., "reservoir controlled by sedimentation and diagenesis, reservoir forming controlled by preservation condition, and production controlled by continuous thickness of reservoir", for marine shale gas enrichment and high yield, six key exploration and development technologies suitable for marine shale gas suffered from multi-stage tectonic evolution in South China have been established, including comprehensive geological evaluation, developmental optimization, horizontal-well optimal fast drilling, horizontal-well volume fracturing, industrial operation, and efficient and clean production, to industrialize the large-scale exploitation of shale gas. By the end of 2019, the proved geological reserves of shale gas in the southern Sichuan Basin submitted by CNPC had exceeded over 1.06×10¹²m³, the production capacity had reached 100×10⁸m³, with the cumulative gas production capacity of 200×10⁸m³. It has made remarkable achievements and accumulated valuable experience. It is of great significance for developing shale gas industry, reducing the dependence on foreign resources, ensuring national energy security, and realizing the "ecological priority and green development" strategy.