Urban rail transit is responsible for a large number of residents’ daily travel services, which is prone to cascading failures when affected by emergencies. Quantifying the failure degree of rail transit stations can provide a basis for the prevention of large-scale cascading failure and the repair of damaged rail transit networks. In this paper, a methodology for quantifying the degree of stations cascading failure in urban rail transit networks based on the coupled map lattice model is proposed, taking into consideration the self-recovery capability of the stations and the loss of passenger flow. Moreover, the reliability of the proposed methodology is verified by comparing the number of damaged stations and the proportion of instantaneous failed stations. The results show that the method can well quantify the failure degree of stations. The change law of the quantified average failure degree of stations is consistent with the change laws of the whole network failure speed and failure scale. When the external perturbation and coupling strength is low, the average failure degree of stations is more sensitive to changes in both, and when the external perturbation and coupling strength are large, the change of the average failure degree of nodes tends to slow down as the external perturbation and coupling strength continue to increase.