对一种结合剪断法和后向散射法测量微纳光纤传输损耗的反射式剪断法进行了优化。通过增加分光耦合器和探测器，用气凝胶固定尾纤，消除了光源波动和尾纤摆动对实验测试的影响。利用该方法测量微纳光纤传输损耗与直径的关系，实验结果表明改进后的方法，测量结果更稳定。

A new method called reflex-cut-back for testing the transmission loss of micro/nano fiber (MNF), which was designed based on combining the methods of cut-back and backscatter, was optimized. By adding coupler and power meter, the influence of source fluctuation and MNF-pigtail swing was eliminated by fixing the MNF-pigtail with aerogel. The relations between the transmission loss and different diameters of MNF were tested with this optimized scheme, and experimental results show that more stable test results could be obtained.