To reduce the setting calculation workload of traveling wave protection for VSC-HVDC lines, this paper proposes an efficient setting calculation method. Firstly, the fault responses of four typical characteristic quantities (CQ) are analyzed, including the rate-of-change-of-voltage, the change-of-voltage, the rate-of-change-of-current, and the change-of-current. The setting principles of the protection criteria based on these CQs are then revealed, indicating that the extreme values of CQs (EVCQ) are required for setting calculation. A novel method is developed to efficiently obtain EVCQs. By exploring the influence of various operating conditions on CQs, the working conditions corresponding to each EVCQ are pre-selected so that EVCQs can be obtained through only several simulations. Finally, the proposed method is validated by a four-terminal VSC-HVDC grid in PSCAD/EMTDC. The setting results through the proposed method are consistent with those through the conventional enumerative method, but the workload of the former is less than one-fiftieth that of the latter. The results demonstrate that the proposed method can significantly improve the setting calculation efficiency while ensuring accuracy.