Big V refers to a "public figure" who is very active in Weibo and has a large number of fans. People who have more than 500,000 "fans" are usually called Internet Big V, where "V" refers to an authenticated account and the English word is "verified". The account will display a V character after its name. It's an account certified by Weibo, and later it became your respectful name.
Most of the big V's are well-known scholars and celebrities, so Weibo's account always attracts a lot of fans' attention, which also makes him the object of help. So "big V" is similar to the original soldier to some extent. Often their forwarding will make a Weibo fire quickly. Some people say that these big V's are actually half media-they always guide comments and topics on the Internet.