Abstract: The oil and gas reservoir in the upper section of Huagang Formation in X gas field is a typical lower-source and upper-reservoir accumulation system. The early research suggested that the H5 layer located in a simple anticline structure and the oil and gas vertically migrated through the source fault on the east side of the anticline and accumulated in the high area of traps. It turned out that the H5 layer was a large-scale braided channel with multistage deposition according to exploration and development. Different sand channel bodies developed independent petroleum systems and different gas abundance. In order to clarify the influencing factors of each reservoir's oil and gas accumulation model, this paper analyzed the distributions, activities and combination patterns of the faults based on the broadband and wide-azimuth seismic data and the maximum likelihood attribute, and pointed out the relationship between faults and hydrocarbon abundance, then established a new accumulation model of the H5 layer. The results show that there are two kinds of advantageous accumulation models in the H5 layer, one of which is the oil and gas migration through the stepped transport system composed of direct source faults and intra-layer faults, and the other is communicating source and reservoir through direct source faults and accumulating upwards to the traps height. The research results guide the well placement in the southern tectonic area and achieve remarkable effects, and have reference significance for the oil and gas exploration and potential evaluation of the same type of oil and gas reservoir.