Embodiments of the present disclosure provide an over-voltage protection method, an over-voltage protection device and a display device. When the voltage value of the output signal is greater than the first preset voltage threshold, it is determined whether the voltage value of the output signal meets the preset over-voltage protection condition. If the voltage value of the output signal is detected to meet the preset over-voltage protection condition, the first control signal is output to stop output of the output signal or lower the voltage value of the output signal.