Method for selecting network node in wireless communication system and device therefor

A network node for selecting a serving Access and Mobility Management Function (AMF) in a wireless communication system, the network node comprising:

• a communication module configured to transmit and receive a signal;
• and
• a processor configured to control the communication module,
• wherein the processor is configured to:
• receive a registration request message of a user equipment (UE), the registration request message including a network slice selection assistance information (NSSAI) for a slice requested by the UE and priority information of the NSSAI;
• determine whether the NSSAI is valid for the UE;
• when the NSSAI is valid for the UE, search a first AMF which is able to support the NSSAI based on the priority information;
• and
• when the first AMF is searched, select the first AMF as the serving AMF serving the UE and transmit the registration request message to the first AMF.