ABSTRACT In the process of rock breaking, the surrounding rock pressures exert a remarkable influence on the rock‐breaking efficiency of disc cutters. This study focuses on the rock‐breaking efficiency of tunnel breaking machine (TBM) disc cutters under varying surrounding rock pressures and temperatures. Firstly, based on the servo principle and linear parallel bonding theory, the discrete element software PFC 2D is used to establish a two‐dimensional simulation rock‐breaking model. Meanwhile, considering the rock temperature, the extent of cutter penetration and specific energy are studied under different conditions. Subsequently, a rock‐breaking experiment platform utilizing cutters is also established to conduct validation. Finally, the findings indicate that the rock fragmentation effectiveness of high temperature rock is 12.56% higher than that of low temperature rock. The cutter exhibits superior efficiency in breaking rocks under low or medium surrounding rock pressure, particularly at a surrounding rock pressure of 8 MPa, with the average specific energy being 8.72% lower than at 4 MPa and 21.03% lower than at 12 MPa, respectively. The maximum error of the simulation model and experiment is 9.51%. A theoretical foundation for the practical implementation of TBM is offered.