The present disclosure relates to network management methods. One example method includes obtaining, by a network slice selection function (NSSF), a configuration parameter sent by a network slice management and orchestration module (NSMAO), where the configuration parameter includes a correspondence, the correspondence includes at least one of a correspondence between single network slice selection assistance information (S-NSSAI) and a network slice instance identifier (NSI ID) or a correspondence between the S-NSSAI and a network slice subnet instance identifier (NSSI ID), and the configuration parameter instructs the NSSF to select, based on the configuration parameter, at least one of a network slice instance (NSI) or a network slice subnet instance (NSSI) for S-NSSAI provided by user equipment.