With the development of the Internet and the advent of the digital era, the Internet has become an indispensable part of people's daily lives. However, along with the development of the network, there are more and more cyber attacks, which not only pose a threat to personal privacy, but also have a huge impact on national security and social stability. Therefore, how to effectively protect our network security has become one of the urgent issues to be solved. In the traditional network security defense, a rule-based approach is usually used for monitoring and analysis, but this approach has certain limitations. Because the network environment is complex and ever-changing, and various types of attacks are emerging, it is difficult to detect and respond to new attacks in a timely manner in the traditional way. More advanced technical means need to be introduced to improve the level of network security assurance. Therefore, this paper proposes a computer vision-based network security detection system based on the summary of existing network security detection methods and the development status of the computer vision field. The main idea of this system is to use computer vision technology to realize the functions of automatic extraction, characterization and classification of network data, so as to improve the efficiency and accuracy of network security detection.