A low-energy consumption Bluetooth IoT device comprises an input interface, a processing module, a Bluetooth module and a display module. An external device transmits a parameter code correlated with a current external information to the processing module through the input interface. The processing module searches out a current bit-series code corresponding to the parameter code from a plurality of bit-series codes pre-stored in the processing module and converts the current bit-series code into a two-dimensional graphic code. A mobile device receives the parameter code broadcasted by the Bluetooth module and uploads the parameter code to a cloud server and then the cloud server converts the parameter code into a current cloud information. The current cloud information is correlated with the current external information.