Concerning the problem of random perturbation of controller in synchronous control of neural network with mixed delays, a non-fragile controller based on event-triggered mechanism was proposed. Firstly, a random variable obeying Bernoulli distribution was used to describe the randomness of the existence of controller gain disturbance. Secondly, the event-triggered mechanism was introduced in the synchronous control process of the neural network. Next, a novel bilateral Lyapunov function was constructed to fully consider the system status information, while the functional derivatives were scaled by an improved integral inequality to obtain sufficient conditions for the exponential stability of the synchronization error system. Finally, a non-fragile controller was designed based on the decoupling technique. The effectiveness of the proposed controller was verified by simulation examples. Experimental results show that compared with the existing exponential attenuation coefficient under the same sampling period in the four-tank system, the exponential attenuation coefficient obtained by the proposed controller is improved by 0.16.