Abstract: This paper designs an improved output-feedback controller from the viewpoint of reducing the control effort at the premise of maintaining the desired control performance for a concrete example. The output-feedback controller guarantees the globally asymptotical stability of the closed-loop system by introducing a new rescaling transformation, adopting an effective reduced-order observer, and choosing ingenious Lyapunov function and appropriate design parameters. Simultaneously, from both the theoretical analysis and a concrete example, smaller critical values for gain parameter and rescaling transformation parameter are obtained to effectively reduce the control effort and the rate of change of controller than the design of the related papers.