In April 1937, he returned to China, joined the Ximeng Association and joined the anti-Japanese work. He used to be the instructor of Puxian Self-Defense Corps and the editor of the Propaganda Department of the Battlefield General Mobilization Committee in the Second World War. In July 1938, he joined the China * * * Production Party, and served as the director of the General Administration of Economy of the Northwest Shanxi Administrative Office, the director of the Policy Research Office of the Central Shanxi District Committee, and the director of the Secretariat. After the founding of the People's Republic of China, he has been engaged in financial, trade and economic work for a long time, and successively served as deputy director of the general office of Southwest Military and Political Committee, vice minister of Southwest Ministry of Finance, deputy director of the second and third offices of China Finance Committee, deputy director of Premier the State Council's office, and deputy director of the State Council Finance and Trade Office. In 1971, he served as the deputy director of the State Planning Commission, in charge of finance, commerce, foreign trade and prices, and concurrently served as the head of the the State Council price group and the head of the fiscal and financial tax reform group. In 1981, he was appointed as a consultant of the State Planning Commission. At the 11th National Congress of the Communist Party of China (the Third Plenary Session of the 11th Central Committee) and the 12th National Congress of the Communist Party of China, he was elected as a member of the Central Commission for Discipline Inspection twice, and concurrently served as honorary president of China Accounting Society and consultant of China Finance Society, China Audit Society, China Price Society and China Materials Society. Duan Yun has a wide range of interests. After work, he likes poetry, calligraphy and Chinese medicine. The main works and works are: Selected Works of Duan Yun's Calligraphy, Poems on Travels, Selected Works of Duan Yun, etc. He has held personal calligraphy exhibitions in Tokyo and Chiba, and served as honorary vice president of China Society of Painting and Calligraphy for the Aged.