After graduating from Beijing Dance Academy in 2008 majored in ballet performance and education, Sun Ruichen joined the National Ballet of China in the same year.

He has performed the leading roles in the Chinese ballets like The Red Detachment of Women, Chinese New Year (The Nutcracker Chinese Version),The Yellow River, The Peony Pavilion, The Crane Calling, The Light of Heart, Inspiration and Glory, and A Dream of Red Mansions. He also danced in romantic ballet La Sylphide, John Cranko's Romeo and Juliet and Onegin, Roland Petit's La Chauve-souris and Carmen, Natalia Makarova's Swan Lake and La Bayadère, John Neumeier's The Little Mermaid and Songs and Dances of the Earth. He danced the main characters in Raise the Red Lantern, Giselle, Don Quixote, Rachmaninoff Piano Concerto No.3, Beethoven: Symphony No. 7, The Firebird, Etudes and etc. as well as many classical ballet pas de deux like La Esmeralda pas de deux, Grand Pas Classique, Diana and Actaeon pas de deux, The Sleeping Beauty pas de deux and modern ballet works such as The White Snake-The Mortal World, Ring the Bell, Land of Exile, Goodbye, My Love, On the Road, Guangling Verse, Sacrifice, etc.

In June 2012, he won the Silver Medal for Senior Males Division in the 7th Helsinki International Ballet Competition, and the Best Pas De Deux Award in the 2nd Beijing International Ballet Dance and Choreography Competition in July, 2013. In 2014, Sun won the "Outstanding Youth Dancer Award" in the Performing Seasons of National Art Troupes for his wonderful performance in La Chauve-souris.

As a guest artist, Sun has been invited to take part in the Gala to celebrate the 50th Anniversary of the Founding of The Australian Ballet in 2012 and the Gala performance in the Ballet Season of Ballet Dortmund in 2013. In 2014, he had a visit to Cuba with President Xi Jinping and danced with Cuban National Ballet at the Ballet Evening Gala. In 2017, Sun starred in Swan Lake at the invitation of the Primorsky Stage of the Mariinsky Theatre.