为研究如何利用脉管制冷机达到４Ｋ温度和最佳多级脉管构型，对几种类型的单级脉管制冷机与Ｇ－Ｍ制冷机组合体进行了实验。当脉管热端温度为室温时采用这种组合体的脉管冷端所获得的最低温度达３．５Ｋ。最后一级回热器的热端大约预冷到１５～２０Ｋ。其最佳工作条件为：压力约１．０～１．５ＭＰａ，频率１～２Ｈｚ。热流和热损失分析与相移效应的关系，以及为达到４Ｋ温度的多级脉管制冷机的构型，均作了简要的讨论。 In order to study how to use the pulse tube refrigerator to reach the 4K temperature and the optimal multi-stage pulse tube configuration, several types of single-stage pulse tube refrigerator and G-M refrigerator assembly were tested. The lowest temperature reached by the cold end of the vessel using this combination reached 3.5 K when the vessel hot end temperature was room temperature. The hot end of the last stage regenerator is precooled to about 15 ~ 20K. The best working conditions for: pressure of about 1.0 ~ 1.5MPa, frequency 1 ~ 2Hz. The relationship between heat flow and heat loss analysis and the phase shift effect, as well as the configuration of a multi-stage pulse tube refrigerator to reach 4K temperature, are briefly discussed.