[5] Sun is the reigning Olympic gold medallist in mixed doubles with Wang Chuqin, and in the team event in both Tokyo 2020 and Paris 2024.

Sun won gold in the women's singles and mixed team with Wang Chuqin at the 2018 Youth Olympic Games in Buenos Aires, Argentina.

In the 2019 World Team Cup, Sun came back from down 10–7 in the deciding fifth game to defeat Mima Ito in the finals against Japan.

[7] However, after China's decision to withdraw from all international events until the Tokyo Olympics,[8] Mima Ito passed Sun for the number two position in the world rankings.

[10] On October 1, in the women's singles final of the Hangzhou Asian Games, Sun defeated Japan's Hina Hayata 4-1 to win gold.