A wireless blue-tooth earphone chargeable by a charging case, includes an earphone shell, an earplug assembled to a bottom of the earphone shell, a speaker unit, a circuit board assembly and a contact assembly. The earphone shell has an accommodating space penetrating through a lower portion of the earphone shell. One end of a peripheral surface of the earphone shell is recessed inward to form a recess. The speaker unit is accommodated in a front end of the accommodating space. The circuit board assembly is accommodated in a rear end of the accommodating space and is connected with the speaker unit. The circuit board assembly is equipped with a plurality of elastic elements. The contact assembly fastened in the recess, has a plurality of conducting elements. The plurality of the elastic elements are electrically connected with the plurality of the conducting elements.