Waverider slide hypersonic vehicle will be very useful for transport and even a powerful weapon in the future. The flight environment is very complex as the hypersonic vehicle flies at high speed and covers wide range, thus the control system of the hypersonic vehicle must have good adaptability. As decoupling pseudolinear system does not have fine dynamic performance, this research established the attitude model of the hypersonic vehicle, using the discoupling method and Block Backstepping theory to design the control system. The stability of close-loop system was proved and the simulation with large flight envelope and large-scale parameters perturbation was accomplished. The results showed that the method can ensure the stability of close-loop system's Lyapunov functions. With functional agility and rapid response, the control system can solve the problem brought about by large flight envelope and large-scale parameters perturbation, and can enhance the system's robustness.