<p>The optimal design of disc cutters that transfer load from the TBM to the rock is a key aspect of TBM cutter head design. In this study, the objective is to examine the influence of the installation angle of the disc cutter on cutting efficiency in the Linear Cutting Test, along with the role of the adjacent two gage disc cutters in rock fragmentation. A set of numerical analysis is constructed using Abaqus software. The Drucker–Prager model and ductile damage were employed to identify and describe the failure modes observed in the rock samples. The work is conducted at a range of installation angles with different cutting spaces. The cutting forces are recorded, and the specific energy, which is defined as the energy required to cut a unit volume of rock, is calculated by counting the removed elements and the rolling force during modeling. The findings of the study indicate that when a single disc cutter is employed, the overall efficiency of the normal disc cutter is the most optimal. Furthermore, the use of adjacent disc cutters has the effect of enhancing the cutting process of gage disc cutters. A review of the results shows that a configuration consisting of the placement of two disc cutters at angles of 0 and 30° adjacent to each other is more effective than other configurations in the majority of scenarios. Additionally, the outcomes demonstrate that the disc cutter with an installation angle of 10° exhibits the lowest performance when making adjacent cuts. </p>