Fluent was used to investigate numerically the internal flow field of combustion-heater for direct-connect scramjet ground test facility.The hydrogen multi-hole injection and hydrogen single-hole injection was computed

respectively.The results show that the exit flow field can meet the design requirements of total temperature 1900 K

Ma=1.85

and the hydrogen single-hole injection is superior to hydrogen multi-hole injection.Meanwhile the computational results also indicate the shortcomings of these two design schemes.