Draw indoor air into the mobile air conditioner. Firstly, the wet cloth curtain in the water evaporator absorbs water for preliminary cooling. The dust in the air will stick to the wet cloth to achieve the dust removal effect. An appropriate amount of bactericidal liquid can also be added to the water for sterilization. The initially cooled air is divided into two groups. One is that the air is directly delivered to the blower that outputs cold air by a variable-speed fan. Another group of air is introduced into the ice water cooling heat exchanger to deepen the cooling and remove the water in the air at the same time. By controlling the ratio of the two groups of air, the temperature and humidity of the output air can be adjusted. The ice water introduced into the ice water cooling heat exchanger is supplied by the speed regulating water pump, which can jointly adjust the temperature of the output air. Finally, the dew condensed on the surface of the ice water cooling heat exchanger is led back to the water tank of the water evaporator. Unlike the general air conditioner, the dew that can absorb heat is wasted.