In order to ensure the cooling rate and low temperature requirements of the test chamber, the refrigeration system of this test chamber adopts a cascade refrigeration system composed of imported compressors. This refrigeration system has the advantages of reasonable matching, high reliability, and easy use and maintenance. After the refrigerant expands adiabatically through the shut-off valve, the refrigerant temperature decreases. The refrigerant absorbs heat from objects with higher temperatures through the evaporator, causing the temperature of the cooled object to decrease. This cycle repeats itself to achieve the purpose of cooling. The design of the refrigeration system applies energy regulation technology, which is an effective way to ensure that the energy consumption and cooling capacity of the refrigeration system can be effectively adjusted under normal operation of the refrigeration unit, reducing the operating costs of the refrigeration system to a more economical state.