Although Sushun was born into nobility, the size of his family meant that he received little attention during childhood, and little expectation from the family. He was neither well versed in literature nor exceptionally able in martial arts. Sushun became a General during the late years of the Daoguang Emperor's reign. Following the death of Wenqing, one of the Xianfeng emperor's closest aides, Sushun was increasingly consulted by the emperor on many important policy matters. His first position in the court was as a member of the Imperial Guard and he subsequently served in a number of senior positions in the Qing government, including a term as the president of the Lifan Yuan. During the Second Opium War, he was one of the chief architects of Qing foreign policy and he repudiated many of the treaties that were concluded in the late 1850s, in particular the territorial concessions in the Sino-Russian Treaty of Aigun.
Following the death of the Xianfeng Emperor in 1861, Sushun, his elder brother Duanhua, and Zaiyuan, along with five other prominent people in the Qing Court, were appointed Regents to oversee administrative affairs during the young Tongzhi Emperor's minority. However, without obtaining the seals of the two Empresses Dowager, the Regency could not carry out any important policy decisions, which led to increased political friction in the imperial court. In November 1861, a triumvirate consisting of the half-brother of the deceased emperor, Prince Gong and the two empresses dowager, Ci'an and Cixi, staged a coup d'état, establishing themselves as the only rightful regents of the boy emperor. All the members of the eight-man council were arrested and Sushun was beheaded in public in 1861 on charges of treason.