Largely due to Cai's extensive experience working in Zhejiang province, he is believed to be a political ally of CCP General Secretary Xi Jinping.

[3] He additionally attended a four-month training program for department and prefecture-level cadres at the CCP Central Party School in 1996.

[2] In September 1996 Cai took on his first major role in local government as the deputy CCP secretary and later mayor of the city of Sanming in Fujian, working there until 1999.

[3] He was transferred to Zhejiang province in May 1999 serving as the deputy CCP committee secretary and Mayor of Quzhou, working there until 2002.

[2][3] Cai additionally pursued a doctoral degree in political economics, which he obtained from September 1999 to July 2001 at Fujian Normal University through part-time studies.

[3] In April 2007, Cai was promoted to the position Mayor of Hangzhou, the provincial capital, also serving as deputy CCP Secretary.

[14] In preparation for the 19th CCP National Congress, Cai called for strengthening social controls and cyber security defense, and cracking down on "various political rumors and harmful information" in September 2017.

[17] At a leaked video of a speech he made a day after fires in southern Beijing on 18 November, Cai said "some should have been cleared long ago, but that’s difficult, so no one dared to do it", referring to unapproved dwellings.

[25] According to the South China Morning Post, Xi appointed Cai to succeed himself as the leader of the Central Cyberspace Affairs Commission in the first half of 2023.

[25] Currently, Cai Qi is seen as one of the most powerful people in China, comparable to Premier Li Qiang and only behind CCP General Secretary Xi Jinping.

[31] In August 2024, he hosted leading scientists from artificial intelligence, quantum physics, deep-sea exploration and aerospace sectors in Beidaihe.

[34] The Economist opined in 2017 as Cai "rocketed up the Communist Party’s ranks" that "Xi Jinping has chosen an unusual man to lead the capital city.

The account was initially opened under the name Qianshui (潜水; literally, "scuba diving"), but he was eventually 'outed' by internet users.

My Weibo can partly solve the misunderstanding between people and government by solving their problems and sincerely talking to them.On the evening of 14 September 2013, a mother of an ordinary government staffer working for the national revenue agency posted on her microblog feed that her son was expected to partake in heavy drinking with superiors on a regular basis as part of his work and that it was affecting his health.

"[41][34] During his four years of using Weibo, he averaged more than six posts a day, which he compiled into a book called "A Room Made of Glass", saying he choose the title to promote transparency.

[36] He also broke conventions, announcing his promotion as the deputy director of the Office of the National Security Commission through Weibo, before the Chinese state media reported on it.

The couple have a son, who previously worked as an official at the subdistrict level in Hangzhou and as a staff member at the National Development and Reform Commission.