The invention relates to the technical field of air-conditioners, in particular to an air-conditioner control method and an air-conditioner. The air-conditioner control method includes the following steps that the air-conditioner enters into a heating mode, and an isolating device is in a started state; actual heating capacity of the air-conditioner is acquired, a heating duration of the air-conditioner entering into the heating mode is also acquired, the actual heating capacity of the air-conditioner is compared with set heating capacity of the air-conditioner, and the heating duration is compared with a set duration; and when the actual heating capacity is smaller than the set heating capacity and the heating duration is longer than the set duration, the isolating device is shut off until the air-conditioner enters into a defrosting mode and then the isolating device is started again. The running time of the air-conditioner under the condition of low heating capacity is shortened, the heating cycle is also shortened, and the ratio of high-efficiency heating duration within the heating cycle is high, so that the heating efficiency of the air-conditioner is improved.