She made her international runway debut during London Fashion Week in February 2010, walking for Christopher Kane.

[6] In December 2009, she was handpicked by Karl Lagerfeld to walk Chanel's Paris-Shanghai fashion show.

In June 2018, Sun graced the cover of Allure magazine, along with Fernanda Ly and Soo Joo Park.

She continues to appear regularly on some of the most highly selective runways in the industry: Alexander Wang, Prada, Valentino, Jil Sander, Christian Dior, Balenciaga, Givenchy, Chanel and others.

However, she fell down twice in a row during the finale owing to the designer's very high heels paired with a slippery catwalk.

[14] In 2014, she became the first East Asian model on the fold cover of the September issue of American Vogue.