Born in Shunde District, Guangdong, Su became interested in the long jump around 2002 and took part in high school and university competitions.

[citation needed] At the 2007 Chinese City Games (China's top junior-level event), he saw off both Zhang Xiaoyi and Li Jinzhe to claim the title with his first ever jump over eight metres (8.07 m).

[1] In 2008, he improved his best by a centimetre, recording a jump of 8.08 m at both the Chinese Olympic Trials (where he was runner-up) and the Shanghai Golden Grand Prix (where he was China's sole medallist).

[2][3] Due to the scheduling of the 2008 Summer Olympics in Beijing, that year's Chinese Athletics Championships were held late in October and Su won his first national long jump title in the absence of more experienced rivals.

[10] Su won the national indoor championships at the start of 2011 and went on to record an outdoor best of 8.19 m to secure second place behind Mitchell Watt at the Diamond League meeting in Shanghai.