Wu was raised in the Jiangxi province of China and began competing in 2011.[2] His success at the national U18 level led him to become a medal contender for the 2015 World U18 Championships in Athletics, achieving a 400 m personal best of 47.60 as just a third-grade senior high student.[3] At the 2015 championships in Cali, Wu advanced past the first round of the 400 m but placed fourth in his semifinal and did not make the finals.[2]
The following year in the 400 m at the World U20 Championships, Wu again qualified for the semifinals and ran a faster time, but did not make the finals again.[2]
At the 2017 National Games of China, Wu won his first Games gold medal as part of the men's relay. He finished 3rd individually in the 400m, a feat he would later repeat in 2021.[2]