Duan Dechang was a member of the Chinese Workers' and Peasants' Red Army. He was born in Nan County, Yiyang, Hunan Province. He joined the Communist Youth League of China in June 1925 and the Chinese Communist Party (CCP) in September 1925. He participated in the Northern Expedition. Around this time, he met Peng Dehuai. In August 1927, after the beginning of the Chinese Civil War between the CCP and the Kuomintang, Duan participated in the Nanchang Uprising. After its defeat, he went to Gong'an County in Jingzhou, Hubei Province.