Abstract: A positioning input system with a wireless charging function, and a device thereof receive a frequency signal sent by a tablet and transmit an sensing signal to the tablet, wherein a rectifier circuit receives the frequency signal inducted by a sensing coil set, including a first sensing coil and a second sensing coil, to output electricity, the first sensing coil is non-connected, the second sensing coil is connected to the rectifier circuit, an oscillator circuit is connected to the rectifier circuit for receiving the electricity and outputting the sensing signal, and a third sensing coil transmits the sensing signal to the tablet. When the wireless positioning device is moved toward the tablet, a magnetic coupling occurs to the first sensing coil and the second sensing coil. The second sensing coil obtains an additional voltage used for supplying a stable operating voltage for the wireless positioning device.