The surface of the large hydraulic track needs thermal treatment for hardening and tempering to improve its wear resistance and bearing capacities. Currently it is still difficult to simulate the hardened layer of the track. For that, this paper firstly put forward a surface layer hardness graded distribution model of the track, and then established a method to measure the hardness of the track in the finite element software. Based on the limit thinking, the meshes of the hardened layer of the track were refined, so as to achieve the purpose of using the discrete mesh to simulate the continuous change of the hardness graded distribution in the hardened layer of the track. Calculation results show that improving the hardness value and the thickness of the hardened layer of the track are benefit to the track’s bearing capacity and deformation stabilization.