Sun's first major appearance was at the 2009 National Games of China where he won two bronze medals. His international debut was two years later at the 2011 World Wushu Championships where he won a gold medal in the daoshu event. He returned to the National Games of China in 2013 and won the silver medal in the changquan, daoshu, and gunshu combined event. A year later, he appeared at the 2014 Asian Games and won the gold medal in the men's daoshu and gunshu combined event. He then won a gold medal in changquan at the 2015 World Wushu Championships, followed by a win in the same event at the first Taolu World Cup in 2016. A year later at the 2017 National Games of China, he finally won a gold medal which he did so in the changquan combined event. Sun then returned to the Asian Games in 2018 and won the gold medal in men's changquan, which was the first medal for China at the 2018 Asian Games.