A thermal management system, a method of controlling the same, a compressor included in the same in which the thermal management system and the method of controlling the thermal management system determine whether the current state is a low-refrigerant state in which a refrigerant amount is smaller than a reference refrigerant amount on the basis of a degree of superheat or a degree of supercooling detected from a pressure and temperature of a refrigerant when a battery thermal management mode is operated and operations of cooling and heating a vehicle interior do not operate. The compressor is included in the thermal management system and configured as an electric compressor configured to be controlled by the control method. Therefore, it is possible to easily recognize whether the current state is the low-refrigerant state in which the refrigerant amount is smaller than the reference refrigerant amount.