Abstract: High-fidelity numerical simulation is considered as an indispensable approach to reveal key physical-chemical process such as ignition, extinction, flame propagation, and stabilization in supersonic flows, and promotes accurate understanding and reliable prediction of complex combustion phenomenon in ramjet engines. However, the extensive spatiotemporal scales caused by the combustion of hydrocarbon fuels in actual engines pose great challenges to turbulent combustion modeling. To overcome these challenges, high-fidelity modeling of complex chemistries in numerical simulation of supersonic combustion should be carefully handled. This paper gives a summary of the main research progresses in turbulence-combustion interaction model, mechanism reduction, and solution acceleration methods in supersonic combustion simulation. Taking typical fuels as prototypes, the high-fidelity modeling of complex chemistries, as well as applicability and influences of different chemical mechanisms in supersonic combustion are introduced. Based on the three-level fidelity evaluation methodology of chemical mechanism, the advantages and disadvantages of reduced mechanism are further clarified, and the necessity and feasibility of using dynamic adaptive chemistry method in the investigation of detailed combustion processes in supersonic flows are also elaborated.