Embodiments of the present disclosure provide an erasing unit for image sticking in a liquid crystal display device, a control method thereof and a liquid crystal display device. A first controlling signal may be generated by dividing a voltage at a DC power supply terminal. A controlling circuit may output a second controlling signal and a third controlling signal in responding to the voltage of the first controlling signal being smaller than or equal to a reference voltage. A charging and discharging circuit may discharge under the control of the second controlling signal and output a high-level voltage signal to an outputting circuit. The outputting circuit may supply the high-level voltage signal outputted by the charging and discharging circuit to TFTs in the liquid crystal display device, controlling the TFTs to be turned on.