Wan joined the Communist Party of China in 1936 and led revolutionary and wartime resistance activities in his native Shandong province. After the founding of the communist state in 1949, Wan served in a series of government ministries, then worked as a member of the municipal leadership in Beijing. He was purged during the Cultural Revolution, but was eventually rehabilitated and returned to work as party chief of Anhui province, where he led the implementation of successful agrarian reforms centered on the household-responsibility system.