Flexible DC technology is widely used in long‐distance and large‐capacity transmission and plays a very important role in realizing the optimal allocation of cross‐regional power resources. However, the protection technology of flexible DC systems is not yet mature. The current differential protection is susceptible to the influence of distributed capacitance, which reduces the reliability of the backup protection of the voltage source converter‐based multi‐terminal DC (VSC‐MTDC) system. To enhance the reliability of DC protection, a new scheme based on virtual traveling active wave power is proposed. First, the concept of virtual traveling wave power is innovatively proposed. Subsequently, the fault characteristics and calculation method of the virtual traveling wave power are provided. Accordingly, a protection scheme based on virtual traveling wave power is proposed and the overall process is given. Finally, a typical VSC‐MTDC system is used to verify the reliability of the scheme.