Embodiments of the present invention disclose a method, an apparatus, and a system for increasing network security. The method for increasing network security includes: receiving, by a network management system, a certificate message reported by a network element; generating, by the network management system, a first list; when determining that a certificate corresponding to certificate information in the first list needs to be revoked, generating, by the network management system, a certificate revocation request file according to the certificate information, and removing the certificate information in the first list from the first list; and sending, by the network management system, the certificate revocation request file to a public key infrastructure (PKI) system.