Abstract: Two-dimension coupled implicit Naviers-Stokes equations and standard k-ε viscid models were introduced to simulate the lift characteristic,drag characteristic,pitching moment characteristic and lift-to-drag ratio characteristic of integrated hypersonic vehicle with Hark head configuration working under the conditions of inlet closed,inlet open but unfired and inlet open and fired.The influence of head slenderness ratio on the aerodynamic performance was discussed.It is concluded that the improvement degree of aerodynamic performance designed with the first method is greater than that designed with the second one,meanwhile,with the increasing of head slenderness ratio,the aerodynamic performance of integrated hypersonic vehicle becomes better in evidence,it can satisfy the aerodynamic requirement of cruising vehicles.