Abstract: Work recovery pulse tube refrigerator(WRPTR)with a displacer as phase shifter has higher efficiency.The main reason is that the expansion power at the heat end of the pulse tube is recovered.The connecting tube between the outlet of the displacer and outlet of the compressor has a significant impact on acoustic power recovery.Through theoretical analysis,the impedance of the acoustic power recovery connecting tube of the pulse tube refrigerator is calculated.The effect of the impedance on the cooling performance is also analyzed.Based on a 1-D simulation model,by changing the length of the connecting tube,the effect of the connecting tube on the cooling performance of the pulse tube refrigerator and the phase angel of regenerator was simulated.It is shows that the WRPTR have the better cooling performance with the shorter connecting tube which has the same inner diameter.Finally,different length of the connecting tube is selected for experimental verification.The results show that with the increase of the length of the connecting tube,the input electric power of the compressor increases obviously under the same refrigeration capacity.