The disc cutter replacement of double-shield TBM in hard rock should be carried out rationally. Hence, the relationship between disc cutter wear and cutter replacement frequency and that between rock broken volume and cutter replacement frequency are established based on theoretical rock broken volume under installation radius of disc cutter, site monitoring data of disc cutter wear and cutter replacement frequency of double-shield TBM used in Maling-Yabao Tunnel on Shenzhen Rail Transit Line No. 10. And then the wear of unit rock broken volume under different disc cutter installation radiuses are obtained according to installation radius and wear of disc cutter, and the effective rock broken cutter wear at different positions and the wear laws of disc cutter at different positions are obtained further. Finally, the wear laws of disc cutter at different positions of double-shield TBM used in Shenzhen hard rock and the disc cutter inspection and replacement rules by taking maximum wear of front disc cutter as cutter replacement control parameter are obtained. The results can provide reference for disc cutter arrangement and replacement of TBM in hard rock of similar project in the future.