[5] During high school, he suffered from a spinal disc herniation and underwent multiple surgeries,[6] which led to him skipping mandatory military service.

[6][7] At the age of 16, he began working part-time as a production assistant while studying at Hwa Kang, including on projects by Chang Hwa-kun, who also offered him a bit part in the Japanese film Rainy Dog which he produced.

[8] After graduating from Hwa Kang, Duan continued working as a production assistant and was invited by Chang to star in films, including the 2000 titles A Chance to Die and The Cabbie.

[8][9] At the age of 19, Duan landed a lead role as Hao-Hao alongside Shu Qi in Hou's 2001 romance film Millennium Mambo.

[27][28] Duan had another breakthrough performance in the 2022 HBO Asia series Twisted Strings [zh], where he portrayed six different characters, including as a mortician, a pimp, a homosexual, and a police detective.