Abstract: By the numerical simulation of the delamination problem of a double-cantilever beam (DCB) , the issues encountered during numerical simulation based on the cohesive zone approach were studied, which was focusd on the quasi-static methods and static methods for calculating the efficiency as well as the stress-strain function of the interface layer for calculating the accuracy and convergence. The calculation implies that the quasi-static method can effectively simulate the process of delamination; and the stress-strain function of the interface layer should have a degenerate course.