An apparatus for controlling an air conditioning system for automotive body painting, the apparatus comprising: a first temperature sensor configured to measure a temperature of outside air; a first humidity sensor configured to measure a humidity of the outside air; a second temperature sensor configured to measure a temperature of supply air that is supplied to a paint booth; a second humidity sensor configured to measure a humidity of the supply air; and a controller configured to calculate a first enthalpy based on the temperature and humidity of the outside air, to calculate a second enthalpy based on the temperature and humidity of the supply air, and to control the air conditioning system for automotive body painting to regulate the temperature and humidity of the supply air when a difference between the first enthalpy and the second enthalpy is outside a reference enthalpy range, wherein the controller is further configured to regulate the temperature and humidity of the supply air based on a total cycle including a temperature control cycle and a humidity control cycle, to transmit a reference control temperature to the air conditioning system for automotive body painting according to the temperature control cycle, and then to transmit a reference control humidity to the air conditioning system for automotive body painting according to the humidity control cycle, wherein the controller is configured to control the air conditioning system for automotive body painting to regulate the temperature of the supply air by the reference control temperature in the temperature control cycle, and then regulate the humidity of the supply air by the reference control humidity in the humidity control cycle, wherein the controller is configured to transmit the reference control temperature to the air conditioning system for automotive body painting until the temperature of the supply air is within a reference temperature range, wherein the controller is configured to transmit the reference control humidity to the air conditioning system for automotive body painting until the humidity of the supply air is within a reference humidity range, and wherein the controller is configured to control the air conditioning system for automotive body painting to alternately regulate the temperature and humidity of the supply air. a first temperature sensor configured to measure a temperature of outside air; a first humidity sensor configured to measure a humidity of the outside air; a second temperature sensor configured to measure a temperature of supply air that is supplied to a paint booth; a second humidity sensor configured to measure a humidity of the supply air; and a controller configured to calculate a first enthalpy based on the temperature and humidity of the outside air, to calculate a second enthalpy based on the temperature and humidity of the supply air, and to control the air conditioning system for automotive body painting to regulate the temperature and humidity of the supply air when a difference between the first enthalpy and the second enthalpy is outside a reference enthalpy range, wherein the controller is further configured to regulate the temperature and humidity of the supply air based on a total cycle including a temperature control cycle and a humidity control cycle, to transmit a reference control temperature to the air conditioning system for automotive body painting according to the temperature control cycle, and then to transmit a reference control humidity to the air conditioning system for automotive body painting according to the humidity control cycle, wherein the controller is configured to control the air conditioning system for automotive body painting to regulate the temperature of the supply air by the reference control temperature in the temperature control cycle, and then regulate the humidity of the supply air by the reference control humidity in the humidity control cycle, wherein the controller is configured to transmit the reference control temperature to the air conditioning system for automotive body painting until the temperature of the supply air is within a reference temperature range, wherein the controller is configured to transmit the reference control humidity to the air conditioning system for automotive body painting until the humidity of the supply air is within a reference humidity range, and wherein the controller is configured to control the air conditioning system for automotive body painting to alternately regulate the temperature and humidity of the supply air.