Offshore oil reservoirs are characterized by loose and heterogeneous strata, high injection-production intensity, and easy water breakthrough along advantageous permeability channels, which can significantly affect development efficiency. The oil reservoir extraction process to an interconnected network of injection were simplified and production wells and developed a novel quantitative identification model for advantageous channels based on inter-well connectivity units. By coupling with a dynamic automatic history matching algorithm, the characteristic parameters of advantageous channels can be obtained directly, accurately and rapidly. Furthermore, a comprehensive evaluation factor of cross-flow intensity was introduced to provide a new method for the classification and characterization of heterogeneous offshore oil reservoirs. Actual field applications show that large channels and advantageous channels can be quickly and accurately identified and predicted, including the vertical development layers, the planar development directions, and the development intensities. Timely guidance for targeted management of low-efficiency channels and sustained high-efficiency development are provided by this method in oil fields.