Abstract: Thermo-chemical non-equilibrium effects may cause decrease in the surface pressure within the expansion region of a high-enthalpy blunt body flow as compared with a frozen flow. Research indicates that a recompression structure appended to the blunt body can eliminate the aforementioned difference. In the present study, a multi-component reactive Euler solver was applied to simulate the hypervelocity flow over a sphere-cone model. The numerical results show that thermo-chemical non-equilibrium induces a nonmonotonic variation to the conic surface pressure, i.e., it decreases first then increases as the recompression angle increases. The underlying mechanism for such a phenomenon is found to be the competing exothermal and endothermal reactions, which is macroscopically reflected by the inhomogeneity of the specific heat ratio in the recompression flowfield.