The present invention discloses a method of balancing wireless load and an Access Controller (AC). The method includes: receiving by an Access Controller (AC) an association request of joining an Access Port (AP) sent by a Station (STA); calculating wireless load of the AP that the STA requests to join; determining whether one or more preset conditions are met, if the one or more present conditions are met, accepting the association request sent by the STA; otherwise, rejecting the association request sent by the STA. In the present invention, when an AP's wireless load is too large, STAs can be distributed to other APs, thereby optimizing load balance in the Wireless Local Area Network (WLAN).