VSC-HVDC transmission is the main transmission mode for large-scale offshore wind power far from the coast transmission to the onshore power grid. In this paper, several implementation methods of bipolar transmission are proposed, and symmetrical monopolar connection is recommended based on the comparison between the symmetrical monopolar and the bipolar connection. In addition, DC voltage optimization scheme is given. The electrical characteristics differences between VSC-HVDC transmission system for the offshore wind farm integration and for other applications are analyzed. Considering the high reliability and compact design requirements of offshore converter stations, as well as the different characteristics of offshore and onshore converter stations, the conclusion of main connection of converter station at both ends is studied and put forward, the configuration of the VSC-HVDC transformers, pre-insertion circuit, bridge-arm reactors, DC energy dissipation devices and the grounding method are analyzed, and the converter station connection schemes of offshore and onshore converter stations are put forward which can simplify equipment requirements, save space and reduce investment on the premise of ensuring reliability.