Tianbao started his professional football career with Changchun Yatai in 2001 after he graduated from their youth team.
When the club brought in Shen Xiangfu as their next manager, Cao found himself dropped from the starting line-up once more; however, this time when used as a substitute he wasn't able to find his goal scoring touch and was allowed to leave for second-tier club Shenzhen Phoenix at the beginning of the 2011 league season.
[7] Despite finishing tenth out of twenty-four teams, the club withdrew from the League before the 2018 season when its owner was under investigation for an illegal fund-raising scandal.
[8] On 20 March 2018, Chengdu Better City was established on its ashes,[9] and Cao remained in its squad as they played within the fourth tier and immediately gained successive promotions.
[10] On 26 March 2021, the contract Cao had with Chengdu would expire, and he joined second tier football club Sichuan Minzu on a free transfer.