Abstract: Voltage source converter based high voltage direct current (VSC-HVDC) is the new generation of HVDC technology, which has outstanding advantages such as avoiding commutation failure, active and reactive power decoupling, stable operation, etc. It has significant contribution to reduce the interaction of AC and DC system and improve the stability of power system. In this article, the technical characteristics and development of VSC-HVDC are introduced, the roles of VSC-HVDC in improving the stability of large grids are discussed, and the engineering experience of VSC-HVDC transmission system in China is shared. New control technology of VSC-HVDC in large grids such as inertia supporting and large-scale renewable energy transmission are also introduced. This paper provides a reference for the development and application of VSC-HVDC technology in the future power system.