In this article, a reliability assessment model based on the morphology characteristics of the ablative region of the contacts is proposed for the change of surface morphology of the contacts. Firstly, the contact morphology evolution process and ablation mechanism are analyzed. The contact images are segmented using the adaptive multi-threshold segmentation algorithm based on the improvement of the image block weight, and the melting and splashing part of the arc-guiding plate is extracted as the region of interest. The area and center of mass of the binary map of the region of interest are analyzed as the two key features of the degradation of the contact performance. The change characteristics of the contact morphology are analyzed, and the change points of different degradation stages of circuit breakers are obtained by the Gath-Geva (GG) fuzzy clustering algorithm, and the multi-stage Wiener degradation model with binary feature correlation is formulated by Copula function. The goodness-of-fit of the KS test is less than 0. 3, and the model is evaluated by the electric life experiments of low-voltage DC circuit breakers.