Abstract: The transformation in philosophy of oil-gas exploration often brings new exploration breakthroughs. Based on the study of the faults in Enping Sag of the Pearl River Mouth Basin, we recognized a new type of fault that is developed in the northern uplift of the steep slope zone of Enping Sag with the following four characteristics: 1） it intersected with the major fault of the sag at a large angle; 2） it became active at the middle stage of the development of faulted lacustrine basin, forming the sedimentary sources channel for sand transport to the lacustrine basin; 3） at the accumulation stage, it cut the source rocks and sand bodies that were input along the faults in the middle faulting period; 4） the internal transport ridge of the fault were formed along the fault strike due to gradual uplifting of strata toward the uplifting area. Under the sealing effect of the regional thick mudstone cover layer, oil and gas migrated along the fault strike. In this study, exploration breakthroughs were made in the northern uplift of the steep slope zone of Enping Sag that is traditionally considered difficult for oi-gas migration and reservoir formation, and now a series of exploration discoveries have been made in this area. The migration mode of oil and gas along fault strike in the Enping Sag of Pearl River Mouth basin can be used as a reference for practice in similar areas.