Web-based industrial control systems are developing rapidly as an important application of information physical systems (CPSs). However, malicious cyber-attacks against industrial control systems in recent years have aroused widespread concern about the security of CPSs. In this regard, this paper proposes an event-triggered performance-preserving control method based on event triggering to cope with denial-of-service attacks. First, considering the random nature of denial-of-service attack behavior, the denial-of-service attack is described as a Bernoulli randomly distributed process with a fixed number of packet drops. Second, to reduce the network communication burden, a discrete event-triggered communication mechanism is used to transmit the measurement information of the sensor. Then, the Lyapunov stability theory and linear matrix inequality method are used to give sufficient conditions for system stability under a denial-of-service attack. Finally, the correctness and effectiveness of the proposed control method are verified by simulation examples.