The invention relates to a digital core two-phase flowing simulation result quantitative representation method based on an erosion-expansion algorithm and application of the method. According to the method, a pore network model of a digital core is extracted through the erosion-expansion algorithm, and quantitative representation of a direct simulation result of two-phase flowing in the digital core is achieved; the saturation of two-phase fluids of all pores and throats is accurately described, the saturation of the two-phase fluids in the pores or throats with the different diameters is described, the defect that a flowing simulation error of the pore network model is large is overcome, and meanwhile the direct flowing simulation result is quantitatively described by using a pore representation method of the pore network model for reference; saturation distribution of the pores and throats with the different diameters has the significance on understanding two-phase flowing in the digital core, the flowing capacity of the fluids in the digital core can be represented according to result, and the diameters of the pores and throats limiting flowing of the fluids are obtained.