He competed in the 2000 Summer Paralympics in Sydney, Australia. There he won a silver medal in the men's Triple jump F11 event, a bronze medal in the men's Long jump F11 event and finished seventh in the men's Javelin throw F11 event. He also competed at the 2004 Summer Paralympics in Athens, Greece. There he won a gold medal in the men's Triple jump F11 event, a gold medal in the men's Long jump F11 event and finished fourth in the men's Javelin throw F11 event. At the 2008 Summer Paralympics in Beijing, China, he won gold medals in the men's Long jump F11 and Triple jump F11 events. He broke the Triple Jump F11 world record in the process. At the 2012 Summer Paralympics he won silver in the Triple jump and bronze in the Long jump.
Li Duan has become known for his showmanship, arriving on the runway still in tracksuit pants, then stripping down to his shorts with a flourish just before commencing a jump.