He hailed from Xinye 新野 in the commandery of Nanyang 南陽 (today in Henan). During the reign of Emperor Shun 漢順帝 (r. 125-144) he rose to the post of palace attendant (xiao huangmen 小黃門), then Palace Attendant-in-ordinary (zhongchangshi 中常侍), and then promoted to commandant of the chariots (che duwei 車都尉).
In 168 he was given the command as palace attendant over the brave-as-tigers battalion of the palace guard (zhonghuangmen huben yulin qianren 中黃門虎賁羽林千人), which allowed him to welcome Emperor Ling 漢靈帝 (r. 167-189), who, acceding to the throne, rewarded him with the title of Marquis of Chang'an Village 長安鄉侯.
At that time, Empress Dowager Dou 竇太后 reigned for the young emperor, and her father, General-in-chief (da jiangjun 大將軍) Dou Wu 竇武 and Senior Mentor (taifu 太傅) Chen Fan 陳蕃 planned to get rid of the eunuch clique that had too much influence on politics. Yet the eunuchs forged an imperial edict appointing Wang Fu 王甫, *overseer of dishes (yujian 食監) of the Changle Palace 長樂, as well as Director of Eunuch Attendants (huangmen ling 黃門令). This allowed them military support, and their troops killed Dou Wu and Chen Fan.
Cao Jie was promoted to the post of Chamberlain for the Garrison (weiwei 衛尉) of the Changle Palace, and given the title of Marquis of Yunyang 育陽. Wang Fu was made Palace Attendant-in-ordinary. Cao was granted the title of Chariot and Horse General (cheji jiangjun 車騎將軍) and soon thereafter was made Director of the Palace Domestic Service (dachangqiu 大長秋).
Cao and Wang Fu invented the news that the Prince of Bohai 渤海, Liu Kui 劉悝, planned a rebellion, and notified this to the emperor. The Prince was killed, and all relatives of the two were highly rewarded with posts in the various commanderies.
Cao Jie bore posthumously the title of Chariot and Horse General.