A scaling method related to the field of network function virtualization (NFV) includes a VNF manager (VNFM) that receives a virtualized network function (VNF) scale out request from an NFV orchestrator (NFVO), where the request includes VNF instance information and indication information that indicates a scale aspect and step; the VNFM determines, based on the VNF scale out request, information about a virtualization deployment unit (VDU) and a corresponding subnet that need to be created; and the VNFM requests creation of the VDU and the corresponding subnet from a virtualized infrastructure manager (VIM).