Abstract: Based on studying kinds of sliding mode observers for linear uncertain system,a novel(robust) sliding mode observer is designed by applying the singular value decomposition to decompose the dynamical system.Then an optimizing sliding model strategy is presented and the strict verification is(conducted) guarantee robustness to uncertainties of systems and disturbances.The Lyapunov function is used as the judgment condition for stabilizing observers,and the convergence rate between the observer and the system is changed by regulating the sliding-mode strategy so as to attain the desired performances of state estimation. Simultaneously,the linear feedback matrix and nonlinear feedback matrix of the robust sliding mode observer are given,and a selected numerical example is used to illustrate the proposed design.