Abstract: Based on systematic organic geochemical research,it is considered that the dark argillite series in the Lower Miocene Sanhaogou Formation is the important hydrocarbon source layer of the basin,the dark argillite series in the Middle-Upper Miocene Huihuan Formation is the potential hydrocarbon source layer.The good paleoclimate conditions and the reducing water medium environment for sedimentation in the Miocene are favorable for the development of the Miocene hydrocarbon source rock series.