报告了液氮温区采用气体混合物作工质的微型节流制冷机的实验研究结果。实验表明，采用混合物工质是提高节流制冷机效率的有效途径。 The experimental results of a micro throttling refrigerator using gas mixture as working medium in the liquid nitrogen temperature region were reported. Experiments show that the use of mixture refrigerant is an effective way to improve the efficiency of throttling refrigerator.