The invention provides an air conditioner and a dehumidification control method thereof. The dehumidification control method of the air conditioner comprises the steps that in a dehumidification mode,the environment
dew point temperature is calculated according to the environment temperature and the environment
humidity, and a first target threshold value temperature range is determined; the first opening degree of an
electronic expansion valve is determined according to the coil
pipe detection temperature of an indoor
heat exchanger of the air conditioner; the second opening degree of the
electronic expansion valve is determined according to the exhaust outlet temperature of a compressor of the air conditioner; and the opening degree of the
electronic expansion valve is adjusted to be the small one in the first opening degree and the second opening degree. The environment
dew point temperature changes along with changes of the environment temperature and the environment
humidity, therefore, it is guaranteed that the coil
pipe temperature of the indoor
heat exchanger is kept within the target threshold value temperature range, the condition that the coil
pipe temperature of the indoor
heat exchanger is too high is avoided, and then the condition that water steam in
indoor air can not be condensed into water is avoided; and meanwhile, influences of the exhaust outlet temperature of the compressor on the opening degree of the electronic expansion valve are avoided, therefore, the dehumidification effect is guaranteed, and the dehumidification speed is increased.