<p>TiN thin film coatings are used to improve the surface hardness of materials. To avoid affecting the shape and size of the workpiece, the coating thickness is usually in the micrometer range. During nanoindentation experiments, the deformation of the material will not be affected by the mechanical properties of the substrate under small indenter load, which is equivalent to the nanoindentation test of the bulk TiN material. Due to the small indentation depth, it is difficult to observe the material deformation and the nucleation and evolution of material defect structures during the experiment. Therefore, molecular dynamics simulation of the nanoindentation process of single-crystal TiN material is an important means to study the nanoindentation deformation mechanism of bulk TiN material. The objectives of previous studies have focused on validating models, calculating specific performance parameters, observing a particular phenomenon, and investigating the influence of a single factor. The present study focuses on the systematic exploration and revelation of the mechanism itself, especially incorporating multiple dimensions such as crystal orientation, depth, and dynamic relaxation behavior. Two kinds of TiN molecular dynamics simulation models with two crystallographic orientations were constructed, and after the model reached equilibrium in the relaxation phase, the single-crystal TiN material was simulated at different indentation depths, the stress relaxation characteristics of the material investigated in the case of different depths, the mechanical property parameters exhibited by load–displacement curves and the defect evolution forms derived from the analysis of the simulation results analyzed, so as to reveal the single-crystal TiN material from the atomic scale The nanoindentation deformation mechanism of single-crystal TiN material has been revealed on the atomic scale.</p>