[2] He was designated as the heir of his uncle, Cao Yu (曹玉), because the latter had no son to succeed him when he died.
In 234, someone reported Cao Hui to the imperial court after he ordered his subordinate(s) to beat up an official in Shouzhang County.
As punishment for his misconduct, Cao Hui had one county with 500 taxable households removed from his princedom.
The number of taxable households in the Dongping princedom increased throughout the reigns of the subsequent Wei emperors until it reached 3,400.
Cao Xi was known for studying medicine and writing books with Huangfu Mi, a physician who lived around the same time as him.