Based on the series-parallel spring stochastic damage model, the cohesive laws of concrete were obtained by the method of energy dissipation equivalence between the damage model and the fracture model. The failure strain of the micro-springs in the series-parallel spring model was assumed to be Weibull distribution and lognormal distribution, based on which the effect of different probability density functions on the cohesive laws was studied. The cohesive laws obtained by the present method were compared with those using the traditional displacement equivalence method. The obtained cohesive laws were also used to simulate the full crack propagation process of three-point notched concrete beams. The results show that the cohesive laws can be affected by the probability density functions and the cohesive laws based on the series-parallel spring stochastic damage model are not affected by the layer number of the model, avoiding the sensitivity problem of spring layers.