[4] His father Shu Heng (舒恆) served as an officer at Wuchang Circuit (武昌, headquartered in modern Wuhan, Hubei).
He later went to live in Jiangxia (江夏, i.e., Wuchang's capital), and the military governor (Jiedushi) Chi Shimei (郗士美) came to be impressed by his talent and often praised him.
[4][6] In 813, during the reign of Emperor Xianzong, Shu passed the imperial examinations and was made the sheriff of Hu County (鄠縣, in modern Xi'an, Shaanxi); he was to be talented and to have gained a good reputation.
It was said that Shu impressed Emperor Wenzong by ruling on criminal cases quickly, such that the backlog dissipated within three months, and thereafter was made deputy minister of justice (刑部侍郎, Xingbu Shilang).
However, it was also said that Li Xun and Shu, in order to gain good reputation, honored senior officials who had been squeezed out by prior chancellors, including Pei Du, Linghu Chu, and Zheng Tan.
Soon thereafter, however, the eunuch-commanded Shence Army (神策軍) soldiers began attacking the governmental buildings, as the eunuchs believed the officials to be complicit with the plot.
Shu changed into civilian clothes and rode out of Anhua Gate (安化門), but was chased down by Shence Army soldiers and arrested.