A network slice deployment method performed by a network slice subnet management function, NSSMF, wherein the method comprises: obtaining network slice subnet requirement information, wherein the network slice subnet requirement information comprises a service requirement that needs to be implemented by a to-be-deployed network slice subnet instance, NSSI; determining an identifier of a network service descriptor, NSD, corresponding to the service requirement and network function information corresponding to the service requirement, wherein the network function information corresponding to the service requirement comprises any one or a combination of the following: one or more network functions corresponding to the service requirement, a connection relationship between a plurality of network functions corresponding to the service requirement, attribute information of a connection between the plurality of network functions corresponding to the service requirement, and a requirement or requirements of the one or more network functions corresponding to the service requirement; and generating a network functions virtualization, NFV, deployment policy for performing NFV deployment of the NSSI, wherein the NFV deployment policy comprises the NSD corresponding to the service requirement or the identifier of the NSD, and a rule that needs to be satisfied for performing network service instantiation based on the NSD, and the rule that needs to be satisfied for the network service instantiation comprises any one or a combination of the following: an identifier or identifiers of one or more virtualized network functions, VNFs, comprised in the NSD, a connection relationship between a plurality of VNFs comprised in the NSD, attribute information of a connection between the plurality of VNFs comprised in the NSD, and a rule that needs to be satisfied by each parameter in a VNFD used by each of the one or more VNFs comprised in the NSD; obtaining, based on the NSD corresponding to the service requirement or the identifier of the NSD, deployment flavours of the NSD; selecting, from the deployment flavours of the NSD based on the rule that needs to be satisfied for the network service instantiation, a deployment flavour that satisfies the rule that needs to be satisfied for the network service instantiation; and sending the deployment flavour to a NFV orchestrator, NFVO. obtaining network slice subnet requirement information, wherein the network slice subnet requirement information comprises a service requirement that needs to be implemented by a to-be-deployed network slice subnet instance, NSSI; determining an identifier of a network service descriptor, NSD, corresponding to the service requirement and network function information corresponding to the service requirement, wherein the network function information corresponding to the service requirement comprises any one or a combination of the following: one or more network functions corresponding to the service requirement, a connection relationship between a plurality of network functions corresponding to the service requirement, attribute information of a connection between the plurality of network functions corresponding to the service requirement, and a requirement or requirements of the one or more network functions corresponding to the service requirement; and generating a network functions virtualization, NFV, deployment policy for performing NFV deployment of the NSSI, wherein the NFV deployment policy comprises the NSD corresponding to the service requirement or the identifier of the NSD, and a rule that needs to be satisfied for performing network service instantiation based on the NSD, and the rule that needs to be satisfied for the network service instantiation comprises any one or a combination of the following: an identifier or identifiers of one or more virtualized network functions, VNFs, comprised in the NSD, a connection relationship between a plurality of VNFs comprised in the NSD, attribute information of a connection between the plurality of VNFs comprised in the NSD, and a rule that needs to be satisfied by each parameter in a VNFD used by each of the one or more VNFs comprised in the NSD; obtaining, based on the NSD corresponding to the service requirement or the identifier of the NSD, deployment flavours of the NSD; selecting, from the deployment flavours of the NSD based on the rule that needs to be satisfied for the network service instantiation, a deployment flavour that satisfies the rule that needs to be satisfied for the network service instantiation; and sending the deployment flavour to a NFV orchestrator, NFVO.