Computer network security is a key field to ensure the security of information in the process of transmission, storage and processing, prevent data from being illegally accessed, tampered with or destroyed, and protect users’ privacy from infringement. With the development of the digital society, computer networks have penetrated into every aspect of our lives, from financial transactions, medical records to government services, all of which rely on the Internet. Therefore, the importance of network security is self-evident. Network system paralysis or data leakage may not only lead to economic losses, but also may cause social chaos, and even affect national security. For example, cyber attacks on critical infrastructure can have serious impacts on power supply, transportation systems, and public services. Therefore, strengthening the computer network security management and improving the defense ability is an indispensable link to ensure social stability and economic development. The feasibility analysis of network security shows that the database transparent encryption algorithm is better than the common information encryption technology in terms of the accuracy and detection time of firewall technology for computer network security under the condition of certain security system evaluation standards.