An air conditioning system for a vehicle and a control method thereof may include a temperature detector; an air conditioning actuator including a cooling device and a blower; and a controller connected to the temperature detector and the air conditioning actuator and including: a load determination portion determining an air conditioning load based on factors including an internal temperature or an external temperature of a vehicle detected by the temperature detector; a storage portion storing a control map that controls the air conditioning actuator according to the air conditioning load; and an update portion updating a control value, pre-stored in the control map, of the air conditioning actuator for the air conditioning load to a demand value of a user when receiving the demand value of the user for the air conditioning actuator.