The detector of DIXE needs to operate stably in an extremely low-temperature environment below 100 mK, achieving such temperatures in space is particularly challenging. The design concept of the DIXE cooling system is shown in the figure below. The cooling chain from room temperature to the cold stage of the ADR consists of a two-stage PTC and a ⁴He JTC. The design utilizes mechanical refrigeration during the pre-cooling stage, eliminating the use of liquid helium to extend its operational lifespan in space. The two-stage thermally coupled PTC provides pre-cooling for the low-temperature stage. Two linear compressors independently drive the cold heads of the two-stage pulse tube refrigerator. The first-stage cold head achieves a refrigeration temperature of 80 K. The first-stage cold head provides pre-cooling to the second-stage cold head via a thermal bridge, while the cold end of the first-stage cold head also supplies pre-cooling to the 80 K shield, the pre-cooling heat exchanger (PHX) of the JTC and the superconducting leads of the ADR. The design temperature of the cold end of the second-stage cold head is 20 K, which will provide pre-cooling for the 20 K shield, the PHX of the JTC, and the superconducting leads of the ADR. In addition to the two-stage PHXs mentioned above, the JTC includes two valve-less oil-free linear compressors, three counterflow heat exchangers (CFHXs), an expansion impedance, and an evaporator. After pre-cooling through the PHXs and CFHXs, the JTC utilizes the Joule-Thomson effect at the evaporator to achieve a temperature of 4.2 K. This part is developed by the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS).