Abstract:Weibei Sag was a strike-slip pull-apart basin, which formed by the strike-slip actives of the Tan-lu fault, and the strike-slip actives played an important role on the evolution of fault system, the forming of the trap, and the hydrocarbon accumulation in Weibei Sag. During the sedimentation of Ek_2 formation, Weibei Sag was in fault-depression stage with weak sinistral strike-slip movement, mainly developed two types faults: tensile fault with nearly east-west direction to northwest direction, and strike-slip fault in northeast to nearly north-south direction. They formed three weak strike slip fault zones according to their positons: named east, middle and west weak strike-slip fault zone respectively. While the sedimentation of Ek_1 formation, the tectonic evolution was changed into right-lateral strike-slip stage, the strike-slip fault with right-lateral strike-slip strongly active, and the direction of tensile fault changed from nearly east-west to northeast by east. The multiple strike-slip activities of Tan-lu fault formed massive strike-slip structure traps and strike-slip extensional traps, and affected or changed the formation of extensional traps and stratigraphic traps, thus provided the trap condition for the hydrocarbon accumulation. In addition, the activities of Tan-lu fault controlled the hydrocarbon accumulation in Weibei Sag. Macroscopic view, the activities of strike-slip fault consulted the uplift of the Zaohu Nose structure belt and the erosion of the overlying strata, provided the dynamics for the oil and gas migration to Zaohu Nose structure belt. In microscopic scales, due to the strike-slip rotation-shearing actions, the oil and gas migrated from west to east along the tensile fault in east-west direction, and sealed by the strike-slip fault in south-north direction. Corresponding to the three weak strike-slip fault belt, the planar distribution of oil and gas in Kongdian formation showed characteristics of “extend in east-west direction” and “zonal distribution in south-north direction”. The middle & north part of the middle weak strike-slip fault belt is the key exploration direction for Weibei Sag at present, and the west weak strike-slip fault belt could to be the study area for tight stone reservoirs and shale oil and gas.