The invention provides a motor, an air-conditioner and a control method thereof. The motor comprises a casing, a rotary shaft, a rotor part, a stator part and more than one bearing. The end portion of the motor is provided with an end cover, the rotary shaft is connected with the rotor part, and the outer end of the rotary shaft penetrates the end cover and extends towards the outside of the casing. The bearings are installed on the rotary shaft and located in a connection region of the rotary shaft and the end cover. The motor is further provided with a bearing heating device. An environment temperature sensing device of the air-conditioner and the motor are electrically connected with a control device. The control device of the air-conditioner judges whether the outdoor temperature is lower than the set temperature T or not, and meanwhile judges whether the air-conditioner is in an operation state or not. When the outdoor temperature is lower than the set temperature T and the air-conditioner is in a shutdown state, the bearing heating device is started. A problem that the motor of the air-conditioner cannot be started due to lubricating grease solidification is solved, the cost improved by grease replacement is reduced, and the reliability of a unit operating under the low-temperature condition is improved.