The temperature-adjustable system of the Space Environment Simulator was introduced, which can keep the thermal shield in the temperature range from 123 K to 423 K. Design method of the main equipments was supplied, and applied to KM2 space environment simulator. The main parameters such as the thermal load of the system, gaseous nitrogen’s mass flow, etc. were calculated, and the fan, main spray equipment and heater were selected according to the calculation result, numerical simulation was also conducted. Test verification has been completed, during the test the cool-down rate is 1.03 K/min and the Uniformity of the thermal shield temperature is better than ±5 K, which match well with the technical index. So the design method can be applied in the development of the similar system. © 2019 International Institute of Refrigeration. All rights reserved.