A network resource management method, comprising: receiving, by a first management unit (700, 710), a service request message, wherein the service request message is used to manage a target service, and the service request message carries target-service requirement information; and obtaining, by the first management unit (700, 710), a network resource based on the target-service requirement information via: - when the first management unit (700, 710) determines that there is a network resource that meets the target-service requirement information: determining, by the first management unit (700, 710) based on the service request message, a network resource that meets the target-service requirement information; and - when the first management unit (700, 710) determines that there is no network resource that meets the target-service requirement information: determining, by the first management unit (700, 710) based on the service request message, first network resource requirement information corresponding to the target-service requirement information, and sending, by the first management unit (700, 710), a first resource request message to a second management unit (800, 810), wherein the first resource request message is used to request a first network resource, and the first resource request message carries the first network resource requirement information; receiving, by the second management unit (800, 810), the first resource request message; and when the second management unit (800, 810) determines that there is a network resource that meets the target-service requirement information: determining, by the second management unit (800, 810) based on the first resource request message, a second network resource that meets the first network resource requirement information; and when the second management unit (800, 810) determines that there is no network resource that meets the target-service requirement information: determining, by the second management unit (800, 810) based on the first resource request message, second network resource requirement information corresponding to the first network resource requirement information, and sending, by the second management unit (800, 810), a second resource request message to a third management unit, wherein the second resource request message is used to request a second network resource, and the second resource request message carries the second network resource requirement information. receiving, by a first management unit (700, 710), a service request message, wherein the service request message is used to manage a target service, and the service request message carries target-service requirement information; and obtaining, by the first management unit (700, 710), a network resource based on the target-service requirement information via: - when the first management unit (700, 710) determines that there is a network resource that meets the target-service requirement information: determining, by the first management unit (700, 710) based on the service request message, a network resource that meets the target-service requirement information; and - when the first management unit (700, 710) determines that there is no network resource that meets the target-service requirement information: determining, by the first management unit (700, 710) based on the service request message, first network resource requirement information corresponding to the target-service requirement information, and sending, - when the first management unit (700, 710) determines that there is a network resource that meets the target-service requirement information: determining, by the first management unit (700, 710) based on the service request message, a network resource that meets the target-service requirement information; and - when the first management unit (700, 710) determines that there is no network resource that meets the target-service requirement information: determining, by the first management unit (700, 710) based on the service request message, first network resource requirement information corresponding to the target-service requirement information, and sending, by the first management unit (700, 710), a first resource request message to a second management unit (800, 810), wherein the first resource request message is used to request a first network resource, and the first resource request message carries the first network resource requirement information; receiving, by the second management unit (800, 810), the first resource request message; and when the second management unit (800, 810) determines that there is a network resource that meets the target-service requirement information: determining, by the second management unit (800, 810) based on the first resource request message, a second network resource that meets the first network resource requirement information; and when the second management unit (800, 810) determines that there is no network resource that meets the target-service requirement information: determining, by the second management unit (800, 810) based on the first resource request message, second network resource requirement information corresponding to the first network resource requirement information, and sending, by the second management unit (800, 810), a second resource request message to a third management unit, wherein the second resource request message is used to request a second network resource, and the second resource request message carries the second network resource requirement information.