Cao Hong was a member of the illustrious Cao family, joining his uncle Cao Cao's forces when he first raised troops during the Yellow Turban Rebellion in 184 AD. Cao Hong later served at Hu Lao Gate and Xingyang in 191 AD, saving his uncle from Xu Rong of Dong Zhuo's Forces in the latter battle. The campaigns of Cao Cao in the 190s took Cao Hong into Yan Province, fighting Lu Bu's Forces, and in 208 AD, led a unit in the Battle of Changban, where he attempted to capture Liu Bei's infant son Liu Chan. He was wounded by Zhao Yun with a spear strike, but survived to fight in the Battle of Chi Bi later that year.
He distinguished himself in 211 AD at the Battle of Tong Gate by holding Ma Chao off as Cao Cao retreated, having 100 passes in a horseback encounter. He fought in the many campaigns of Cao Cao in the 210s AD and 220s AD, and again fought in the Northern Expeditions. In 232 AD, after having been wounded at the Battle of Jie Ting in 229 AD, he passed away.