Specializing in the freestyle, he won a gold medal in the 100 metre freestyle at the 2015 World Championships.
At the 2014 Asian Games, he won gold medals in the 50 metre freestyle, 4 × 100 metre medley relay, 4 × 100 metre freestyle relay, and 100 metre freestyle, breaking the Asian records in the latter two events.
Ning also swam for China at the 2016 Summer Olympics.
On March 6th 2019, Ning announced his retirement from competitive swimming through his Weibo account, on his 26th birthday.