The fundamental principle of voltage source converter based high voltage direct current（VSC-HVDC） power transmission is introduced. Combined with Shanghai Nanhui VSC-HVDC demonstration project， the hardware configuration and software structure of control and protection systems of VSC-HVDC made in China are described. Simulation results with real-time digital simulation（RTDS） are also introduced， which show the good performance of the control and protection system both at steady and transient conditions so as to suitable application in practical engineering.