Abstract: In this paper,the operating characteristics and energy of R410A single-medium cascade refrigeration sys-tem are analyzed.Exergy loss and exergy efficiency of each component and the whole system were analyzed by conven-tional exergy analysis method.The results showed that when the frequency of high and low temperature compressors was increased,the cooling capacity of the system was increased,and the COP of the system increased firstly and then de-creased.Exergy loss of low-temperature evaporator,low-temperature compressor and high-temperature compressor is high,which is the weak part of the system.When the frequency of high and low temperature stage compressor exceeds 200 Hz,the frequency of compressor continues to increase,the rate of exergy loss increases,exergy efficiency decreases,and COP of the system performance parameter starts to decline.The low-temperature compressor frequency has a greater impact on the system performance than the high-temperature compressor frequency.