Air interface key update method, the core network node and a wireless access system

The present invention discloses a method for updating the air interface key, the core network node and a wireless access system, wherein the updating method comprising: a core network node migration target RNC receives a message indicating completion of the relocation complete indication message for instructing the user equipment UE migrated from the source RNC to the target RNC successfully; conventional case of using the storage key and the key to calculate the current enhancement hop enhanced key; the next hop key to the enhancement of the said target RNC. By the present invention, to secure effective protection of the user's front, thereby improving the overall security of wireless access communication system.