Utilizing voltage source converter based high voltage direct current transmission is the future trend for large-scale long-distance wind farm integration. With the continuous operation of related projects, the control and protection technology for VSC-HVDC systems with wind farms has become the current research focus. Based on actual projects, this paper reviews the research achievements and development status of the VSC-HVDC system with wind farm integration from several aspects, such as system topology, steady state control, small disturbance stability, active frequency response, AC and DC coordinated operation and transient control. The technology difficulties of current projects are introduced, and the future direction of research is prospected.