A method and device for accessing and obtaining UE context and UE identity are provided. The method for access includes: when a UE accesses an SAE network, judging, by a network node, whether a GUMMEI carried by the UE or an MMEGI in the GUMMEI is allocated or mapped by the SAE network; if the GUMMEI or MMEGI is allocated by the SAE network, selecting, by the network node, an MME according to the GUMMEI, or according to the MMEGI and an MMEC, or according to a PLMN-id, the MMEGI and the MMEC; and if the GUMMEI or MMEGI is mapped by the SAE network, selecting, by the network node, an MME according to an MCC, an MNC and an MMEC in the GUMMEI. Therefore, the access of the UE is achieved.