Following his studies in Beijing, Cui traveled with a Chinese delegation to the United Nations to work as an interpreter in the General Assembly.

After working in the UN for five years, Cui returned to academia to pursue a postgraduate degree from Johns Hopkins University's Paul H. Nitze School of Advanced International Studies in Washington, D.C.[3] After graduating from Johns Hopkins University, Cui joined the Ministry of Foreign Affairs, first as a deputy director of the Department of International Organizations and Conferences, and then as spokesman for the Information Department.

When Cui saw the shortlist of the universities that the Americans recommended, he roared: "There's no way he's going to East China Normal, I will not share an alma mater with that man!

"[9] On March 6, 2013, Cui was interviewed by reporters from China Youth Daily when he attended the National People's Congress.

[10] On October 8, 2013, Cui delivered a speech at the School of Advanced International Studies at the Johns Hopkins University.

He said some Japanese believe that: "During World War II, Japan was only defeated by United States and her atom bombs.