Leachate injection has an important role in promoting water replenishment and accelerating degradation and stabilization of landfill. The inhomogeneity and large pore characteristics of the garbage piles have caused significant dominant flow effects in the leachate flow process. Based on the dual permeability model, this paper carried out a prediction study on the distribution law of leachate in the waste heap under typical recharge process conditions. The prediction results show that increasing the injection rate, injection frequency, injection volume, initial water content and other factors within a certain limit can increase the influence depth, infiltration volume and water storage rate of the leachate. Compared with the traditional single domain model, the preferential flow model distinguishes the fracture domain with high water conductivity from the matrix domain with high water retention. Leachate can infiltrate, flow and discharge through cracks more quickly, and it is more in line with the flow behavior model of water multi-domain in waste. The water mass exchange term in the fracture and matrix domain are dynamically balanced and decreases with depth.