Disclosed are an NAS connection establishment method and a radio access network node, the method includes: a radio access network node receiving, from a machine type communication (MTC) user equipment (UE), an Access Stratum (AS) message carrying a non-access stratum (NAS) request message, wherein the AS message carries a request reason of the AS request message; the radio access network node converting the request reason in the AS message into priority indication information and sending a signaling to a core network node, wherein the signaling includes priority indication information and the NAS request message carried in the AS message; the core network node determining the priority of the NAS request message based on the priority indication information in the signaling, and when the core network has a congestion, the core network node sending a rejection response message to a UE that sends an NAS request message with a low priority.