His grandfather Cui Jing (崔儆) served as a secretary general of the executive bureau of government (尚書省, Shangshu Sheng).
[2] He was later made Sixun Yuanwailang (司勛員外郎), a low-level official at the ministry of civil service affairs (吏部, Libu) as well as imperial scholar (翰林學士, Hanlin Xueshi).
It was said that, contrary to the previous years, when emperors felt compelled to discuss the commissions of chancellors with powerful eunuchs, Cui's commission was made suddenly, with Emperor Wuzong only having informed the imperial scholar Wei Cong (韋悰) to have Wei draft the edict, without the prior knowledge by the other chancellors or the eunuch directors of palace communications (Shumishi) Liu Xingshen (劉行深) or Yang Qinyi (楊欽義).
[6] He was subsequently sent out of Chang'an to serve as the governor (觀察使, Guanchashi) of Shanguo Circuit (陝虢, headquartered in modern Sanmenxia, Henan).
[6] He eventually came to carry the titles of Zuo Pushe (左僕射, one of the heads of the executive bureau (尚書省, Shangshu Sheng)), Menxia Shilang (門下侍郎, deputy head of the examination bureau), administrator of Daqing Palace (大清宮), chief scholar at Hongwen Pavilian (弘文館), and the Duke of Boling.
Emperor Xuānzong thus made Cui's colleague Bai Minzhong the supreme commander of the forces facing the Dangxiang.
[7] In 852, with agrarian rebels occupying Mount Ji (雞山, in modern Nanchong, Sichuan), Emperor Xuānzong dispatched the general Wang Zhihong (王贄弘) to the region to deal with them.
)[7] In 855, with Huainan Circuit (淮南, headquartered in modern Yangzhou, Jiangsu) suffering from a famine, but the military governor Du Cong not governing the circuit diligently, Emperor Xuānzong removed Du from the post and sent Cui out to Huainan to serve as its military governor, continuing to carry the Tong Zhongshu Menxia Pingzhangshi title as an honorary title.