This application discloses an authentication and association method and system. An access point AP receives an authentication request sent by a station STA that needs to establish a connection to a service device; the AP establishes authentication with the STA; after the STA sends an association request to the service device, the AP receives an authentication result query request sent by the service device, and sends a result of the authentication result query request to the service device, so that the service device determines whether to establish an association with the STA; if the result shows that the STA is authenticated by the AP, the service device can establish an association with the STA; or if the result shows that the STA fails to be authenticated by the AP, the STA cannot establish an association with the service device.