The invention discloses an air conditioner high voltage detection method and device. The method comprises the steps of detecting a state of a high-voltage switch of an air conditioner; detecting an operating state of the air conditioner under the condition of continuously keeping the high-voltage switch in an off state for a first preset time length; and determining whether the high-voltage protection treatment is performed on the air conditioner according to the operating state of the air conditioner. According to the air conditioner high voltage detection method and device, the technical problem of high false alarm rate in an existing air conditioner fault detection technology is solved.