During March 2011, Su set a new Chinese national 60 metres indoor record in Chengdu with a time of 6.56 seconds. He went on to establish himself as his country's top male sprinter that year: he won the 100 m title at the 2011 Asian Athletics Championships in a personal best of 10.21 seconds, was the bronze medalist at the 2011 Summer Universiade, then competed at the 2011 World Championships in Athletics in Daegu (running in the heats of the relay). He ended the season by breaking the Chinese record to win the 100 m at the Chinese Athletics Championships with a time of 10.16 seconds, improving upon Zhou Wei and Chen Haijian's former best mark.