A Bluetooth earphone includes a main body, an earpiece disposed at one side of the main body, an ear hanger, a power unit, and first and second rotating shafts. The ear hanger includes a first end portion disposed on the earpiece, a bent-back portion bent from the first end portion, and a second end portion extending from the bent-back portion. The power unit includes a battery set disposed removably on the second end portion of the ear hanger, and a transmission cable electrically connected to the main body and the battery set. The first rotating shaft unit connects the earpiece pivotally to the main body. The second rotating shaft unit connects the ear hanger pivotally to the earpiece. The Bluetooth earphone is adjustable to be worn on the left or right ear of a user, and is convenient to replace the battery set.