The invention discloses a control method for accumulating liquid of a fresh air ventilator heat exchanger of an air conditioner. The control method includes the steps that when the fresh air ventilator heat exchanger is in a heating work mode, whether the fresh air ventilator heat exchanger has accumulating liquid or not is judged; if yes, the fresh air ventilator heat exchanger is controlled to be switched to a bypass work mode; in the heating work mode, refrigerants discharged by a compressor of the air conditioner pass through the fresh air ventilator heat exchanger and an outdoor heat exchanger and then circulate to the compressor; and in the bypass work mode, the refrigerants discharged by the compressor of the air conditioner pass through a fresh air ventilator bypass pipeline and the outdoor heat exchanger and then circulate to the compressor. The invention further discloses the air conditioner. The liquid refrigerants are prevented from accumulating in the fresh air ventilator heat exchanger until the accumulating liquid in the fresh air ventilator heat exchanger is fully discharged, so that the energy efficiency of the fresh air ventilator heat exchanger of the air conditioner in a low-temperature environment is improved.