Abstract: A comprehensive numerical model of a two-stage GM cryocooler was developed using Sage software and validated against experimental results.Based on this numerical model and exergy analysis methods, the distribution of losses in the compressor, rotary valve, and cold head at various refrigeration temperatures was analyzed.The results indicate that the majority of the losses occur in the compressor and rotary valve.The losses in the cold head increase as the refrigeration temperature decreases, with 36% of the losses occurring in the cold head at 4.2 K, of which 61% are due to the effects of real gas.The inefficiency of the compressor, rotary valve, and regenerator, along with the real gas effects, predominantly contribute to the losses in the cryocooler, leading to its low efficiency.