To effectively restrain a continuous commutation failure of an HVDC system at different degrees of fault, an improved voltage-dependent current order limiter (VDCOL) controller design scheme based on adaptive voltage limits is proposed. First, this paper makes a detailed analysis of operating characteristics of an HVDC system with VDCOL involved during commutation failure and recovery. At the same time, the dynamic performance of the VDCOL curve over different periods is proposed. Then, the time-varying DC current, which can reflect the fault characteristics, is introduced to optimize the upper and lower limits of the DC voltage of a conventional VDCOL. Thus, the starting voltage threshold and the variation trend between voltage and current instruction are adaptively changed in different periods, meeting the dynamic active and reactive power demand of the transmission system. Knowing that an excessive change of the voltage limits will deteriorate the system operational characteristics, its range is analyzed and rationally selected. Finally, the proposed method is simulated and tested in PSCAD/EMTD. The simulation results show that the improved control strategy can suppress the continuous commutation failure of the HVDC system to a certain extent and effectively improve the operation characteristics of the HVDC system at each fault stage. This work is supported by the Science and Technology Project of State Grid Corporation of China (No. 5100-202199545A-0-5-ZN).