A charging protection device comprises a universal serial bus (USB) interface, a resistance circuit, a detection circuit and a control circuit. The universal serial bus interface includes a configuration channel. The resistance circuit includes a pull-down resistor coupled between the configuration channel and a ground GND. The detection circuit is configured to detect an abnormal charging condition. The detection circuit generates an abnormal signal when the abnormal charging condition occurs. The control circuit is coupled to the detection circuit and configured to change a voltage value on the pull-down resistor to be out of a preset voltage range according to the abnormal signal.