Ling began his career as a functionary in regional branches of the Communist Youth League in his native Shanxi Province. His Youth League involvement propelled him to the national-level organization in 1979. At the Youth League Ling worked in its propaganda department and edited its flagship newspaper. Closely following the footsteps of his patron Hu Jintao, Ling was promoted to a leadership position in the General Office of the Communist Party of China in 1999, and became an important member of the State Commission for Public Sector Reform.
Ling was one of the highest-profile targets (next to Zhou Yongkang and Xu Caihou) of the anti-corruption campaign following the 18th Party Congress spearheaded by Party General secretary Xi Jinping and central discipline chief Wang Qishan. He was the second sitting "national leader"-level figure to be investigated by the party's anti-graft agency, after CPPCC Vice-Chairman Su Rong. Chinese-language media have linked Ling to a mysterious political network composed of prominent politicians and businesspeople with origins in Shanxi called the Xishan Society.