He is the Olympic Silver medalist (2016 Rio de Janeiro and 2024 Paris) and twice consecutive world champion (2017 Budapest and 2019 Gwangju) in the 100 meters backstroke.

Xu is the current national record holder in backstroke races in all distances (50, 100, and 200 metres).

[12] At the 2017 World Aquatics Championships, Xu became the first male Chinese swimmer to win gold in the 100m backstroke in a time of 52.44 seconds.

He swept the backstroke events and was part of the Asian record setting mixed and men medley relays.

[13][14] At the 2019 World Aquatics Championships, Xu successfully defended his 100m backstroke title with a time of 52.43 seconds.