Abstract: The peak value of the continuous operating voltage including commutation overshoot is an important parameter that determines the reference voltage of the DC arrester in the converter station. Based on the Changji-Guquan ±1100 kV UHVDC project, the models of main equipment including converter valve, converter transformer, flat wave reactor and PLC filter are established. The PCOV level of each type of DC arrester is simulated according to the equivalent circuit model of the ±1100 kV UHVDC converter station. Compared with the results calculated by the formula method, the simulated PCOV level is consistent on the whole, with the maximum deviation of 13.4%, indicating that the formula method still has a certain safety margin. Based on the models established in this paper, the influencing factors of PCOV are further analyzed, and the results show that the damping resistance, damping capacitance, the iron inductance of the saturated reactor, the leakage inductance of the converter transformer and the inductance of flat-wave reactor have a great influence on PCOV calculation.