Abstract: Compact and efficient micro refrigeration systems are promising candidate for cooling electronic devices with the increasing heat flux.In this paper,the refrigeration performance of a micro pulse tube refrigerator using siliconbased regenerator was simulated with Fluent 19.0 software.The influence of porosity,cold-end temperature and phase angle were studied.The results show that the porosity of silicon-based regenerator has an important effect on the refrigera-tion performance.There is an optimal porosity of regenerator to get the highest COP of refrigerator when the geometric parameters are fixed.The micro pulse tube refrigerator can get a cooling power of 3.844 W at 293 K when the operating fre-quency is 500 Hz,the porosity is 0.87,the calculated COP is 1.007 and the relative Carnot efficiency is 3.44%.The cooling power of the refrigerator increases with the cold-end temperature,but the relative Carnot efficiency decreases with the increase of cold-end temperature.This study provides theoretical guidance for the design and development of the miniaturized refrigerator.