An intelligent entrance guard unlocking method includes: transmitting electric energy by wireless electromagnetic radiation via a transmit coil; receiving the electric energy via a receive coil; capturing a vein image of a part of a user via a number of small cameras by Infrared scanning technology and filtering noises from the vein image to get a filtered vein image; transmitting a wireless signal containing the filtered vein image to an intelligent entrance guard; comparing the filtered vein image with a predefined vein image; unlocking the intelligent entrance guard when the filtered vein image matches with the predefined vein image and not unlocking the intelligent entrance guard when the filtered vein image does not match with the predefined vein image.