Abstract: Based on the analysis of a large number of logging, core, analysis and testing data, the Neogene hydrocarbon reservoir formation in Gaskule oilfield was studied from the aspects of structural characteristics, sedimentary microfacies, diagenesis, etc., and the main controlling factors of Neogene reservoir in the area were clarified. The results show that the structure controls the distribution of the reservoir, and the reservoir mainly develops in fault nose structure and accumulates in high position, the micro amplitude structure also controls the accumulation of local oil, the fault has lateral sealing effect on the formation of the reservoir; the sedimentary microfacies of underwater distributary channel and mouth bar are favorable facies for oil and gas accumulation. The diagenesis that really controls the distribution of oil sands is only cementation. The sand body in the area is dense due to cementation, which can form cementation zone on the plane, and has lateral sealing effect on oil and gas migration.