This application provides a VNF instantiation method and apparatus, applied to various NFV systems, to implement an existing VNFD model—defined VNF. The method includes: An NFVO obtains a VNFD, where the VNFD is for instantiating a VNF, the VNFD includes first indication information and resource requirement information of a first internal network, and the first indication information indicates that the resource requirement information of the first internal network is externally visible. Then, the NFVO sends an external network instantiation request to a VIM, where the external network instantiation request is used by the VIM to instantiate, based on the resource requirement information of the first internal network, an external network connected to the VNF. Then, the NFVO sends a VNF instantiation request to a VNFM. The VNF instantiation request is used by the VNFM to instantiate the VNF based on the VNFD.