Abstract: With the continuous increase of coal mining depth, the problem of mine heat hazard has become more and more serious. As a mainstream technology of heat hazard control, ground centralized refrigeration and cooling system has many advantages, such as convenient condensation heat discharge, high refrigeration and cooling efficiency, and simple and reliable equipment system, and is widely used in the mining of large deep mines in China. The composition of the ground centralized refrigeration and cooling system is briefly described, with a focus on the core equipment pressure coupling device to achieve pressure conversion between the primary high-pressure cold-water and the secondary low-pressure hot-water, and the application status of the device is analyzed. Based on the actual underground process, a pressure coupling pilot-scale device testing platform was built to evaluate the fluid characteristics of the independently designed and developed pressure coupling pilot-scale device. Based on the set control strategy, the pressure, flow rate, and flow resistance loss characteristics of the device were investigated under three operating conditions: rated flow rate of 30 m³/h and reduced flow rates of 25 and 20 m³/h, with the pressure of about 11.5 MPa in primary high-pressure circuit, the pressure of about 4.5 MPa in secondary low-pressure circuit, and a flow rate of the primary and secondary circuits that were basically equal. The results indicate that the set control strategy is logically reliable, executed accurately, and achieves fast and orderly switching between different strokes of the device. At a rated flow rate of 30 m³/h, the maximum amplitude of flow fluctuations in the high and low pressure circuits is 1.14 m³/h (3.9%) and 3.20 m³/h (10.6%), respectively, and the flow fluctuation of low-pressure circuit is more obvious than that of high-pressure circuit, but the overall fluctuation amplitude is limited; The maximum amplitude of pressure fluctuations at the high-pressure inlet and outlet of the device is 0.38 MPa (3.3%) and 0.41 MPa (3.6%), respectively, and the maximum amplitude of pressure fluctuations at the low-pressure inlet and outlet is 0.17 MPa (3.7%) and 0.21 MPa (4.8%), respectively, and the pressure fluctuations in both circuits are relatively small; The flow resistance losses of the high and low pressure circuits are 180 and 150 kPa, respectively, which are basically consistent. Under the working conditions of reducing the flow rate to 25 and 20 m³/h, the changes in flow rate and pressure of the device are similar to the characteristics of the rated flow rate of 30 m³/h, indicating that the device has significant flexibility in flow operation.