Wireless power transmission device

A wireless power transmission device (4) includes a main body (40), a first position-limiting bulge (43), a second position-limiting bulge (44), and a closed transmitter coil (45). The first and second position-limiting bulge are disposed within the main body. A space is defined between the first and second position-limiting bulge. The closed transmitter coil is penetrated through the space. The two sides of the coil are respectively in contact with the first and second position-limiting bulge, so that the coil is shaped as a dumbbell. Since the coil is shaped as a dumbbell, the magnetic flux can be uniformly generated by the electromagnetic effect when the coil is magnetized. The wireless charging efficiency is enhanced.