In the information age, the rapid development of computer network technology has changed the ways of people’s work, study and life. And for the computer network environment, a series of safety problems exist. The computer network security problem has already drawn the attention of the public. It needs to be solved to improve the reliability of computer network to prevent the computer network safety risk effectively. This paper studies and discusses how to improve the reliability of computer network, and puts forward a series of countermeasures and methods for reference.