Considering the uncertain long time-delay of networked control systems（NCS），the problems of modeling and stability of NCS are discussed and analyzed. If the sensor node of NCS is time-driven，the actuator and the controller are event-driven，the sampled data are lumped together into a single data packet and the NCS with uncertain long time delay is modeled as a discrete linear system with uncertain time-delay. Then based on Lyapunov stability theory，sufficient conditions of asymptotic stability of closed-loop systems are derived，and the state feedback controller is obtained based on the feasible solution of the linear matrix inequalities（LMI）. The simulation results verified that this method is valid for the uncertain long time-delay problem of NCS.