A method of synchronizing notification messages for electronic devices (20, 30a, 30b), comprising: - monitoring, by an electronic device, if it has a notification message; - if the electronic device has the notification message, determining, by the electronic device, if it is on standby; - if the electronic device is determined to be on standby, determining, by the standby electronic device, if an active electronic device associated with the standby electronic device and having a valid communication address is present; - if the standby electronic device determines that the active electronic device is present, the standby electronic device sends the notification message to the active electronic device; - if the electronic device is active, the electronic device displays the received notification message; - by the standby electronic device, timing a first preset wait period and determining if the active electronic device has displayed the notification message; - if the standby electronic device determines that the active electronic device has displayed the notification message, then the active electronic device is configured to determine if the first preset wait period has passed; - if the standby electronic device determines that the first preset wait period has not passed, the standby electronic device receives a message that the active electronic device has displayed the notification message, wherein the step of determining, by the standby electronic device, if the active electronic device associated with the standby electronic device and having a valid communication address is present and the step of determining, by the standby electronic device, that the active electronic device is present and sending, by the standby electronic device, the notification message to the active electronic device comprises: - the electronic device sends a request message to a management server, wherein the request message is used to request a communication address list of active electronic devices, and the request message carries a message identifier; - the management server responds to the request message and sends the communication address list of active electronic devices to the standby electronic device according to the message identifier; - determining, by the standby electronic device, if at least one valid communication address is present in the communication address list; - if it is determined by the standby electronic device that at least one valid communication address is present, the standby electronic device sends the notification message to the active electronic device having a valid communication address. - monitoring, by an electronic device, if it has a notification message; - if the electronic device has the notification message, determining, by the electronic device, if it is on standby; - if the electronic device is determined to be on standby, determining, by the standby electronic device, if an active electronic device associated with the standby electronic device and having a valid communication address is present; - if the standby electronic device determines that the active electronic device is present, the standby electronic device sends the notification message to the active electronic device; - if the electronic device is active, the electronic device displays the received notification message; - by the standby electronic device, timing a first preset wait period and determining if the active electronic device has displayed the notification message; - if the standby electronic device determines that the active electronic device has displayed the notification message, then the active electronic device is configured to determine if the first preset wait period has passed; - if the standby electronic device determines that the first preset wait period has not passed, the standby electronic device receives a message that the active electronic device has displayed the notification message, wherein the step of determining, by the standby electronic device, if the active electronic device associated with the standby electronic device and having a valid communication address is present and the step of determining, by the standby electronic device, that the active electronic device is present and sending, by the standby electronic device, the notification message to the active electronic device comprises: - the electronic device sends a request message to a management server, wherein the request message is used to request a communication address list of active electronic devices, and the request message carries a message identifier; - the management server responds to the request message and sends the communication address list of active electronic devices to the standby electronic device according to the message identifier; - determining, by the standby electronic device, if at least one valid communication address is present in the communication address list; - if it is determined by the standby electronic device that at least one valid communication address is present, the standby electronic device sends the notification message to the active electronic device having a valid communication address.