From 1982 to 2003, Sun worked in Ministry of Finance and State Taxation Administration, China. In April 2003, he was appointed as the Director-General of Income Tax Department, State Taxation Administration, China. In July 2008, he was appointed as the Director-General of the General Office, State Taxation Administration, China. In September 2009, he was appointed as Secretary-General of the Leading CPC Members Group and the Head of the Liaoning Provincial Tax Office, State Taxation Administration, China. In September 2013, he was appointed as the Chief Auditor of State Taxation Administration, China. In October 2014, he was appointed as the Chief Accountant of State Taxation Administration, China. In January 2016, he was appointed as member of the Leading CPC Members Group, Deputy Commissioner of State Taxation Administration, China. In July 2018, he was appointed as CPC Committee member and Deputy Commissioner of State Taxation Administration, China.