With the rapid development of computer technology and Internet technology, people gradually enter the modern era of information. Using a variety of modern means of information, people’s work and life become more convenient. But at the same time, there are criminals making the network security attacks. The security of network database is threatened, and the transmission and processing of information are affected, therefore a set of perfect security mechanism of network database needs to be developed to ensure the network database security. This article briefly introduces the basic concepts of network database security mechanism, network database model and its security mechanism model, analyzes the network database security mechanisms in each layer, and discusses on the use of DBMS security mechanism to prevent network attacks, so as to improve the network database safety and provide some suggestions.