At some point, he passed the imperial examination and thereafter was made the magistrate of Yingcheng County (應城, in modern Xiaogan, Hubei).
The reviews, conducted by the ministry of civil service affairs, were initially not positive, as Wei was said to have allowed some of his official business to be delayed and was unfamiliar with old regulations.
However, Emperor Gaozong respected Chu and recalled him to be a chancellor again in 652, after which Wei could not be promoted and was at one point demoted to the post of magistrate of Qingshui County (清水, in modern Tianshui, Gansu).
He stated to Wei, "You, sir, are not just a small fish in the pond, but I would like to ask you to serve for a few years to watch out for the foundation of this princely mansion."
Early in Emperor Gaozong's Yongchun era (682–683), Wei served as Shangshu Zuo Cheng (尚書左丞), one of the two secretaries general of the executive bureau, and then as imperial censor.
If Tian Renhui has deluded Your Imperial Majesty and accused Zhang Renyi of terrible crimes, then this also means that I have not served the emperor well.
In 685, he was created the Baron of Bochang, and he was also given the designation Tong Fengge Luantai Sanpin (同鳳閣鸞臺三品), making him a chancellor de facto.
Empress Dowager Wu agreed and allowed him to retire, bestowing on him the honorific title Taizhong Daifu (太中大夫).