According to the system characteristics of ±350 kV Luxi back-to-back VSC-HVDC transmission project for asynchronous interconnection between Yunnan Power Grid and China Southern Power Grid, key technical principles are proposed for the design and type selection of the VSC-HVDC valve AC side wall bushing considering the requirements of system equipment adaptability, parameter configuration, typical structure selection, monitoring device and test inspection. The research shows that key influencing factors, such as system topology and grounding bias leading to AC and DC voltage superposition, various operation mode resulting in wide range fluctuation of voltage and current, different installation location affecting the rated current calculation, should be considered during the design of VSC-HVDC wall bushing. Both the dry-capacitor type structrure form and the dry-inflation type structrure form of wall bushing are analyzed, and it is proved that temperature compensation function is not needed in the SF₆ pressure monitoring device of the wall bushing. Research results of this paper have been applied to the design and type selection of the wall bushing of ±350 kV Luxi back-to-back VSC-HVDC project.