The problem of observer-based robust H_∞ controller design for networked switched control systems with random time-varying delay and uncertainties is studied. Firstly, the time varying delays in data transmission are modeled as a random sequence satisfying a Bernoulli distribution. Then, under the switching signal with average dwell time(ADT), an observer-based controller which can estimate states and measure robustness to disturbance of the system is developed. Finally, by using a Lyapunov-Krasovskii function(LKF), a sufficient condition is developed to ensure the system mean square exponential stability with a satisfied H_∞ performance criterion, and the solutions for the observer and controller are obtained in terms of linear matrix inequalities(LMIs). Simulation results show the effectiveness of the proposed method.