The discovery of Puguang Gas Field should be attributed to the innovation of exploration ideas, geological understanding and the development of exploration technologies. By anatomizing the exploration history of Xuanhan-Daxian area, this paper analyzed the formation of structural-lithologic complex trap exploration strategy in Puguang area, expounded the new geological understanding of predictive models of deep-ultra deep high quality carbonate reservoirs and the technical ideas of complicated carbonate reservoir prediction. The discovery of Puguang Gas Field has contributed to the development of deep strata exploration in the Yuanba, Heba and the whole Sichuan Basin, and established the solid resources basis for the "Gas Pipeline from Sichuan to China Eastern Region"  Project.