Because Xiao Daocheng was a Liu Song general who contributed in military campaigns, Xiao Ni served in a number of low-level government posts early in his life, including as a county magistrate and as an administrator in the census bureau.
By 477, the young but violent and arbitrary Emperor Houfei was universally feared by officials and the people, for he was in the habit of roving outside the palace with his guards, killing all humans or animals that they came in contact with.
In 479, Xiao Daocheng had Emperor Shun yield the throne to him, ending Liu Song and starting Southern Qi.
Soon after the establishment of Southern Qi, Emperor Gao recalled Xiao Ni back to Jiankang to serve as the governor of the capital region, Yang Province (揚州, modern Zhejiang and southern Jiangsu), a highly important post, and a post that he would retain for the rest of his life.
As a special honor, Emperor Wu also made Xiao Ni's wife Princess Yu be in charge of the ancestral worship of their parents and grandparents.
In words that he left his five sons, he stated: The high praise that Xiao Ni received in official histories might be related to the fact that his fifth son Xiao Zixian (蕭子顯) was the official who was later, in the succeeding Liang Dynasty, commissioned to author the official history of Southern Qi, the Book of Qi.