His elder brother Xue Mingjian [zh] (1895–1980) was a politician in the government of the Republic of China.

After the Chinese Civil War, he held positions as head of the Department of Heavy Industry, Shanghai Military Control Commission; Assistant Commissioner, State Statistical Bureau; Director, Economics Institute at the Chinese Academy of Sciences; Commissioner, Fifth Session of Chinese People's Political Consultative Conference; Delegate, 12th National Party Congress; member, Advisory Commission of the Central Committee of the CCP; member, State Council Academic Appraisal Committee.

Sun advocated market-oriented reforms and was denounced by Maoists as "China's Liberman" (referring to the Khrushchev-era economist Evsei Liberman) as a result of a damaging association with Liu Shaoqi, who was known as "China's Khrushchev".

[1] He was associated with the career of pioneer post-Marxist Chinese liberal Gu Zhun, acting as the latter's protector during anti-Rightist purges to which he himself was eventually to succumb.

[1] Sun married Feng Keping (洪克平), and had an adopted daughter named Li Zhao (李昭).