Hypersonic flows generally involve highly complex physical phenomena induced by high-temperature effects. Therefore, the chemical and thermal non-equilibrium states in the hypersonic regime require the simultaneous numerical analysis of thermochemical reactions and flow dynamics due to their coupling. In this study, a CFD code for thermochemical non-equilibrium flow analysis is developed based on a compressible RANS solver. Various thermochemical models and additional conservation equations are implemented to numerically represent chemical reactions, relaxation processes, and gas species along with their properties. Validation is conducted for several two-dimensional, axisymmetric, and three-dimensional problems. The results show good agreement with experimental data and previous numerical studies. The capability of the present solver to simulate thermochemical non-equilibrium hypersonic flows is successfully verified.