Abstract: The nonlinear finite element method is applied to analyze the surface heat treatment indices of large-scale hydraulic steel-gate wheels and tracks. A parabolic model of the gradient distribution of hardness and the relationship between the hardness and Young’s modulus and the yield strength are established, respectively, to simulate the influence of heterogeneous materials in the hardened layers. The results show that the stress state and the deformation dynamically depend on the hardened layer depth, surface hardness values and the hardness matching extent of the wheel and the track. The hardened layer depth and the hardness matching extent of the wheel and track are suggested. A method of determining heat treatment indices is also proposed.