Xu is known for his work in birational geometry, the minimal model program, and the K-stability of Fano varieties.

After completing his PhD doctorate at Princeton under János Kollár's supervision,[1] Xu joined MIT as a CLE Moore Instructor between 2008-2011.

After a promotion to assistant professor at the University of Utah, Xu returned to Peking University in 2012 to join the Beijing International Center of Mathematical Research, subsequently promoted to professor in 2013.

In 2016, he was announced as a winner of the ICTP Ramanujan Prize for that year, "in recognition of Xu's outstanding works in algebraic geometry, notably in the area of birational geometry, including works both on log canonical pairs and on Q-Fano varieties, and on the topology of singularities and their dual complexes.

[3] He was elected as a Fellow of the American Mathematical Society in the 2020 Class, for "contributions to algebraic geometry, in particular the minimal model program and the K-stability of Fano varieties".