The invention discloses a resource application method, a VNF instance creation method and a device. The method comprises the following steps: after determining the number of to-be-applied resources, the VNF sends a resource application message to a VNFM, wherein the resource application message is used for the VNFM to perform resource application according to the number of the to-be-applied resources; and the VNF receives a resource application result returned by the VNFM. It can be seen that, in a resource application process in the embodiment of the invention, interaction between the VNF andthe VNFM is introduced, since the VNF can flexibly determine the number of the to-be-applied resources according to resource needs, the resource applied by the VNFM is enabled to flexibly satisfy dynamic variation of the resource needs; moreover, the number of the to-be-applied resources is generated dynamically by the VNF, thus, compared with a mode of artificially preparing a VNFD file in advance in the existing technology, the method provided by the invention is more convenient and practicable.