He obtained the highest degree (jinshi) in the imperial examination and was selected a shujishi of the Hanlin Academy in 1850.

During the Boxer Rebellion, he advocated using the Boxer to support Empress Dowager Cixi's declaration of war against the Westerners,[3][4] Xu Tong and Chongqi, two high court officials in Beijing, submitted a memorial to the court unambiguously demanding the killing of all Chinese Christians and foreigners in China.

[5] In the memorial he wrote "regardless of which province or place, if there are foreigners in the territory, the people should kill them directly."

However, when the Boxers besieged the International Legations, they burned, killed and looted, even Xu's house was not spared.

Later, the victorious Eight-Nation Alliance named Xu Tong as one of the masterminds behind the rebellion.