Full section tunnel boring machine (TBM) is widely used in the construction of city underground space with the characteristics of fast driving speed, safety, and high efficiency. Disc cutter as an important part of cutting rock mass on TBM cutter head, disc cutter directly cuts and breaks rock mass during tunnelling construction, and wear problem of disc cutter is the most common and unavoidable problem during TBM tunnelling construction and the stress characteristics of disk cutter directly determine its service life. In this paper, the wear forms and rules of the disc cutter of shield machine are classified，based on the feedback information of tool wear during the TBM excavation construction of Shenzhen Metro Line 13. Then, based on the tribology theory of metal and rock breaking theory of mining, the mechanical models of rock breaking under different wear conditions and at different stages of disk cutter are established according to Mckyes-Ali model. At the same time, the J-C constitutive model and HJC model after failure are used to solve the nonlinear impact and dynamic response problems of the disc cutter broken rock mass with wear failure, which verifies the accuracy of the theoretical model. Finally, based on the key parameters of TBM driving and geological parameters, and the least square method is used to predict the wear condition of the disc cutter, in combination with the engineering practice the error optimization analysis is carried out and a better prediction result is obtained. This paper provides an important reference for mechanical analysis, cutter head optimization, driving parameter optimization, TBM design, and associated engineering works.

Disc cutter,Cutting rock mass,Dynamic response,Mckyes - Ali model,Nonlinear analysis