The utility model discloses an external bluetooth device based on a smart phone. The external bluetooth device comprises an environmental data acquisition module, a data acquisition circuit, an information acquisition data processing module and an information acquisition data storage module, the environmental data acquisition module is connected with the information acquisition data processing module through the data acquisition circuit and a wireless transmission module, the information acquisition data processing module is connected with a touch screen through the information acquisition data storage module, the wireless transmission module comprises a bluetooth module A and a bluetooth module B, the bluetooth module A is electrically connected with the data acquisition circuit, the bluetooth module B is electrically connected with the information acquisition data processing module, the bluetooth module A and the bluetooth module B are mutually matched, and a wireless communication is performed between the bluetooth module A and the bluetooth module B. According to the external bluetooth device based on the smart phone, the design is novel, various environmental data information can be acquired by the environmental data acquisition module, the data can be transmitted to a processing module and a storage of the phone through the wireless transmission module, then acquisition results can be displayed on the touch screen, and the touch screen can be operated visually and concisely.