This paper focuses on fault detection when there is time-varying delay, packet loss, and nonlinear sensor sectors in nonlinear network control systems.In order to solve the problem of network resource waste caused by time-triggered periodic sampling, an event-triggered mechanism is proposed, in which the sampled data needs to be transmitted only when a certain triggering condition is satisfied.Based on Lyapunov stability theory and Linear Matrix Inequality (LMI), the fault detection problem is transformed into an H∞ convex optimization problem.Finally, simulation of the motor servo control system is conducted through Matlab, and the validity and practicability of the design are proved.