Abstract: The hypersonic aero-thermodynamics is important for me night control and me vehicle themal protection system (TPS) design. This paper firstly studies the thernlodynamic environment in the thermochemical nonequilibrium now unstmcnlrized girds are used to simulate the towed Ballute night in the Earth atmosphere and the Maniall atmosphere by DSMC. Important parameters of the hypersonic Vehicle, including the themochemical nonequilibrium chamcteristics and the wall heat nux, are obtained by me numerical simulation. The obtained results are compared wim the computatiOn results published by NASA Langley research center, and a good agreement is found. These results are useful for designing related vehicles'TPS.