The prescribed?time control of fully actuated cascaded strict-feedback nonlinear systems has hardly been explored， though such systems are widely applied in the fields such as missile guidance， missile interception， and spacecraft attitude control. Therefore， a prescribed?time controller design method based on Backstepping control strategy was proposed. In the method， backstepping concept and non?scaling design method were combined， which means not scaling the system states， virtual control laws were designed directly to construct the controller. The stability of the designed controller was demonstrated through proof by contradiction via analysis of the time derivative of the system’s Lyapunov function， ensuring that all system states converged asymptotically to zero within the specified time. The time is independent of initial conditions and can be set freely within physical limits. Numerical simulation results verify the effectiveness and practicality of the proposed controller.