After a long period of water flooding, the sandstone reservoir enters the high water cut or extra high water cut development stage, it was formed the dominant seepage channel of water drive, reservoir heterogeneity and inefficient and ineffective water circulation are the main contradictions in oilfield development. Based on Darcy's law, it was analyzed the formation reason of the dominant seepage channel of water drive. Taken the injection-production well group in Nanpu X fault-block as a unit, mainly based on comprehensive discriminant parameters such as permeability level difference and water injection intensity, combined with the Rdos grid numerical simulation results, supported by geological characteristics and tracer identification method, it was identified comprehensively the dominant seepage channels in the study area, it was determined the development horizon and distribution law of the dominant seepage channel of water drive. The research results provide an important reference for the formulation of the next step of reservoir exploitation measures.