An enhanced adjoint method for solving two point boundary value problems is proposed and applied to trajectory optimization problems for a rocket based high speed suborbital launch vehicle,and smooth control serials are obtained indirectly.The first order Taylor Expansion is used to the nominal trajectory which is calculated by the enhanced adjoint method.High robust,high accurate tracking result is obtained under disturbance boundary constrains by receding horizon control technology which is featuring prediction ability.The simulation results demonstrate the capacity and reliability of this proposed method.