The disclosure discloses a method for updating and generating an air interface key and a radio access system. The updating method comprises: a source Radio Network Controller (RNC) completes the static relocation towards a target RNC; the target RNC performs intra-Serving-RNC (SRNC) relocation; during the intra-SRNC relocation, the target RNC updates enhanced key of itself according to a key received from the source RNC or a core network node. With the disclosure, the enhanced air interface key can be updated during the SRNC static relocation process without increasing the time delay of the SRNC relocation, and security and efficiency of the system are improved.