Du graduated from law department of Jilin University with a master's degree. He joined the CCP in March 1966.
In early years, Du served in FAW Car Co., Ltd in Changchun and Communist Youth League Jilin committee. From September 1984 to 1991, he served as vice secretary of CCP Changchun municipal committee, a standing committee member of CCP Jilin committee, director of organization department in Jilin, and vice secretary of CCP Jilin committee. In March 1992, Du became the CCP Deputy Committee Secretary of Hainan. He was elected the chairman of Hainan People's Congress in February 1993. From February 1998 to August 2001, Du was the CCP Committee Secretary of Hainan. From August 2001 to December 2006, Du served as Minister of Agriculture. In December 2006, he became the CCP Committee Secretary of Sichuan, and was elected chairman of Sichuan People's Congress in January 2007. In December 2007, Du succeeded Liu Yandong as the director of United Front Work Department of CCP Central Committee.