A device management method, wherein the method comprises: obtaining, by a first network management device, subscription parameter information, wherein the subscription parameter information indicates a subscription parameter used during a process of establishing a first subscription session, and the first subscription session is used to indicate a first network device to send subscription data to a network management device managing the first network device; and after the first network management device determines that the first subscription session is interrupted, generating, by the first network management device, a request message, wherein the request message comprises the subscription parameter information, and the subscription parameter information in the request message is used to establish a second subscription session; the second subscription session is used to indicate a network device managed by the first network management device to send subscription data to the first network management device; and the network device managed by the first network management device comprises a second network device or the first network device; and sending, by the first network management device, the request message to the network device managed by the first network management device, characterized in that: wherein the network management device managing the first network device comprises a second network management device; and the first network management device and the second network management device belong to a same network management device cluster, and the first network management device is a standby device of the second network management device; or the first network management device belongs to a first network management device cluster, the second network management device belongs to a second network management device cluster, the first network management device is an active device in the first network management device cluster, and the first network management device cluster is a standby network management device cluster of the second network management device cluster. obtaining, by a first network management device, subscription parameter information, wherein the subscription parameter information indicates a subscription parameter used during a process of establishing a first subscription session, and the first subscription session is used to indicate a first network device to send subscription data to a network management device managing the first network device; and after the first network management device determines that the first subscription session is interrupted, generating, by the first network management device, a request message, wherein the request message comprises the subscription parameter information, and the subscription parameter information in the request message is used to establish a second subscription session; the second subscription session is used to indicate a network device managed by the first network management device to send subscription data to the first network management device; and the network device managed by the first network management device comprises a second network device or the first network device; and sending, by the first network management device, the request message to the network device managed by the first network management device, characterized in that: wherein the network management device managing the first network device comprises a second network management device; and the first network management device and the second network management device belong to a same network management device cluster, and the first network management device is a standby device of the second network management device; or the first network management device belongs to a first network management device cluster, the second network management device belongs to a second network management device cluster, the first network management device is an active device in the first network management device cluster, and the first network management device cluster is a standby network management device cluster of the second network management device cluster. wherein the network management device managing the first network device comprises a second network management device; and the first network management device and the second network management device belong to a same network management device cluster, and the first network management device is a standby device of the second network management device; or the first network management device belongs to a first network management device cluster, the second network management device belongs to a second network management device cluster, the first network management device is an active device in the first network management device cluster, and the first network management device cluster is a standby network management device cluster of the second network management device cluster.