Cao Haiqing started his professional football career in 2011 when he was loaned to Wenzhou Provenza's squad for the 2011 China League Two campaign.
[2] He made his Super League debut on 27 May 2012 against Henan Jianye, coming on as a substitute for Kim Dong-jin in the 70th minute.
[4] On 28 February 2017, Cao transferred to fellow Super League side Jiangsu Suning after Hangzhou was relegated to the second tier.
[6] He would struggle to become a regular within the team and go on loan to second-tier football club Kunshan for the 2020 China League One campaign.
[8] On 29 April 2022, Cao joined top-tier club Cangzhou Mighty Lions for the 2022 Chinese Super League campaign.