Abstract: Ice accretion on the insulator causes serious hidden hazards, which is danger to the normal operation of transmission lines. The study on the flashover model of ice-covered insulator is helpful to guide the insulation state assessment of power system operating in ice and snow areas. Given that the arc resistance represented by the existing model is not clear, it is fully considered that the arc during the flashover of ice-accreted insulator is composed of ice surface arc and gap arc. Thus, the arc resistance is regarded as the sum of two kinds of time-varying arc resistance, and the criterion of arc development is modified. By observing the DC flashover process of iced insulator on site, the flashover channel consists of two opposite arcs at the high-voltage and low-voltage ends. Based on the above flashover path, double-arc dynamic circuit model of DC flashover on ice-covered insulator is elaborated. The results indicate that the flashover voltage and critical flashover current calculated by the model are close to the experimental results, and the errors between them are 11.9% and 8.9%, respectively. Moreover, the leakage current waveform and arc speed calculated by the model are basically consistent with the measured results. Consequently, the experimental values are in good agreement with the calculated results.