Abstract: This study presents a three-dimensional numerical simulation investigating the flow and thermal environment characteristics of a hydrocarbon-fueled oblique detonation combustor. The accuracy of the numerical method was validated through oblique detonation combustion experiments under typical inflow conditions. The three-dimensional flow field characteristics in the oblique detonation combustor under non-uniform inflow conditions are analyzed, with particular focus on the effects of equivalence ratio and wall thermal barrier coating thickness on the flow structures and thermal environment. Results indicate that due to non-ideal effects, such as inflow non-uniformity and boundary layer influences, the wave system and combustion characteristics exhibit significant variations across different spanwise cross-sections of the combustor. The wall thermal environment is governed by the oblique detonation combustion wave structures, leading to a highly non-uniform distribution of wall heat flux. The equivalence ratio modulates the structure of the oblique detonation combustion field, thereby altering the thermal environment. However, under various equivalence ratios, the peak wall heat flux is consistently located at the wedge leading edge and the sidewall region behind the oblique detonation wave. The sidewall has the largest area and therefore requires the most cooling, followed by the wedge wall, and then the bottom wall. The heat transfer required for cooling the combustor surface increases with the equivalence ratio. Increasing the thickness of the thermal barrier coating has negligible effects on the oblique detonation combustion characteristics but effectively insulates the metal substrate of the combustor from high-temperature combustion gases, thus significantly reducing the heat flux density at the combustor surface.