The invention provides a power enterprise information network security management system having a security pre-warning function. The power enterprise information network security management system having the security pre-warning function comprises a firewall, a gateway, an intrusion prevention system IPS, a security system, an access control and isolation system and an identity authentication system; and the security system comprises a security monitoring module, a security pre-warning module, a security response module, a security analysis module, a security alarm module, a security operation and maintenance module and a security evaluation module. Due to setting of the security pre-warning module, the security pre-warning module can give a corresponding pre-warning prompt according to the monitoring information of the security monitoring module; a pre-warning threshold value is pre-set in the security pre-warning module; when a pre-warning value is less than the pre-warning threshold value, the security pre-warning module gives a pre-warning prompt; when the pre-warning value is greater than the pre-warning threshold value, the security pre-warning module directly gives an alarm prompt; therefore, interruption of the system operation after an alarm is directly given due to inaccurate or incomplete monitoring information can be avoided; therefore, the working continuity of the system is ensured; and thus, the working efficiency of the system is increased.