Embodiments of the present disclosure describe a network slice determining method and system, and an apparatus. As discussed with respect to the embodiments described herein, in the communications field, a network slice to which a terminal belongs can be determined for the terminal in a 5G network. The method may include obtaining, by a network selection function (NSF) node, an identity of a terminal. The method may also include sending, by the NSF node, the identity to a home subscriber server (HSS), and then receiving, by the NSF node, a slice identifier of the network slice that is sent by the HSS, where the slice identifier is determined by the HSS based on the identity The method may also include determining, by the NSF node based on the slice identifier, a network slice to which the terminal belongs.