In this paper, a guidance law with terminal velocity constraint is proposed to attack the target point with expected terminal velocity for hypersonic morphing vehicle. The motion model and aerodynamic model of hypersonic vehicle with variable span characteristic are established. Based on the motion model, The analytical desired velocity profile is established. Then the velocity tracking guidance law is designed based on additional attack angle. Furthermore, the span deformation is utilized to assist the adjustment of induced drag, aiming to achieve small miss distance and velocity deviation. Finally, the feasibility of proposed method is demonstrated through numerical simulations.