The present disclosure relates to the field of Internet of Things, and in particular, to an online upgrade method and apparatus for a Bluetooth cluster. The online upgrade method for the Bluetooth cluster includes: an upgrade device selects a central node in the Bluetooth cluster and establishes a Bluetooth connection with the central node; the upgrade device selects an upgrade path, and sends upgrade data to a to-be-upgraded device through the central node according to the upgrade path, enabling the to-be-upgraded device to obtain the upgrade data to achieve an upgrade, where the to-be-upgraded device includes a part or all of Bluetooth devices in the Bluetooth cluster. The online upgrade method of the Bluetooth cluster adopted in the present disclosure further broadens a communication range of the Bluetooth, which requires no one-to-one operation by a user.