Born in Shengzhou, Zhejiang in January 1960, Su Deliang graduated from Central Party School of the Communist Party of China.
Su began his political career in September 1980, and joined the Communist Party of China in March 1985.
In August 1999, he was transferred to southwest China's Hainan and appointed deputy head of Hainan Provincial State Security Agency, and a member of the party committee, he served there until August 2002.
In August 2002, he was transferred again to North West China's Ningxia Autonomous Region, where he became its deputy secretary-general, party boss and head of its Provincial State Security Agency, and was re-elected in March 2005. He also served as Secretary of the Political and Legal Committee from December 2006 to May 2013, and he was a member of its CPC Standing Committee between June 2007 to May 2013.
In May 2013, Su Deliang was promoted to become a member of the Ministry of State Security of the Communist Party of China, and concurrently served as its Director of the Political Department. In August 2015, he was promoted again to become Vice-Minister of State Security, replacing Ma Jian, who was stripped of his post for alleged "serious violations of discipline and laws" during the Chinese government's ongoing anti-corruption campaign.