This paper investigates the filtering problem for network-based uncertain systems. The networked filtering system is modeled as a switched system with time-delay by the delay input approach, and such a system consists of two subsystems. Using the piecewise Lyapunov function approach, Jensen's integral inequality and the average dwell time method, a sufficient condition is obtained to guarantee that the filtering error system is exponentially stable, and the filter design method is presented in terms of linear-matrix inequalities (LMIs). Finally, a numerical example is provided to illustrate the effectiveness of the proposed filter design method.