Abstract: The problem of fault detection for delta operators networked control systems (NCSs) with two-channel packet losses and time-varying delays is investigated. Here, it is assumed that packet losses occur during data transfer from controller-to-actuator and sensor-to-controller and that two independent Bernoulli random variables are used to indicate whether packet loss has occurred. The above NCSs are modeled as networked switched systems, and the design method of fault detection filter under an arbitrary switching law is given. The sufficient conditions of the exponential mean-square stability of the considered networked switched system are obtained using linear matrix inequalities (LMIs) approach, Lyapunov-Krasovskii functional, and average dwell time. It is proved that the system satisfies the H_∞ performance. The explicit expression of the desired filter parameters is derived. A numerical example is presented to verify the effectiveness of the proposed method.