Abstract: Free piston Stirling cryocooler is a regenerative cooler with compact structure,high efficiency,low noise and high reliability.In order to reduce the production cost and simplify the manufacturing process of the regenerator,the random stainless steel fiber matrix and the wound polyimide film is used to fill the regenerator,respectively.Sage software is used to simulate the whole machine.Firstly,the effects of the filling parameters of the regenerator on the cooling performance are studied.Secondly,the production cost of both fillers is estimated and the flow and heat transfer characteristics are com-pared.Then,exergy losses of cooler components are analyzed.Finally,the structure parameters of the regenerator filled with the wound film are optimized.The results show that the wound polyimide film filling regenerator has obvious perfor-mance advantages compared with the random stainless steel fiber matrix.The relative Carnot efficiency in terms of acoustic power for the wound film is 56.2% at 30 W@77 K,which is relatively 16% higher than that of the random fiber matrix.