1. A method for obtaining information of an instance label, comprising: sending, by a managing device, a SearchLabel Request, wherein the SearchLabel Request carries information of an index label and the index label is used by the managing device for citing an object instance; and receiving, by the managing device, a SearchLabel Response, wherein the SearchLabel Response carries the information of the instance label corresponding to the information of the index label and the instance label is configured to cite the object instance by a managed device, wherein the information of the instance label comprises a path of the object instance, and wherein the path comprises the instance label, and wherein: the SearchLabel Response comprises a first parameter and a second parameter, the first parameter indicates whether the index label exists in the managed device, the second parameter comprises a structure array and indicates mappings between index labels and instance labels, the managed device is configured to send a Label Deletion event to the managing device, and the Label Deletion event indicates that one or more object instances and/or index labels is deleted from the managed device.