The invention discloses an energy saving system employing radiation refrigeration. The energy saving system comprises a first liquid storage device, a second liquid storage device, a radiation refrigeration device, a data acquisition system and a control unit, wherein the first liquid storage device and the second liquid storage device communicate with an application end pipeline, the radiation refrigeration device is in pipeline communication with the first liquid storage device and the second liquid storage device, the data acquisition system is used for acquiring temperatures of an outlet end of an application end and an outlet end of the radiation refrigeration device and a liquid level of the radiation refrigerating system, and the control unit is in communication control with the data acquisition system, a first adjustment valve, a second adjustment valve, a third adjustment valve, a fourth adjustment valve and a fifth adjustment valve and is used for controlling on or off of thefirst adjustment valve, the second adjustment valve, the third adjustment valve, the fourth adjustment valve and the fifth adjustment valve according to the temperature acquired by the data acquisition system. The invention aims to provide the energy saving system employing radiation refrigeration, the energy consumption is reduced, and the energy saving system is environmental-friendly.