基于保偏光纤(PMF)偏振耦合原理设计了分布式保偏光纤应力传感系统。对一长为1050 m的保偏光纤进行了实验,确定了系统的测量灵敏度和空间分辨率。测试了耦合强度与应力大小的关系及温度对系统的影响。实验结果表明,该传感系统能检测大于1000 m的保偏光纤,测量灵敏度和空间分辨率随光纤长度的增加而逐渐衰减,温度低于100℃时,其波动对测量影响很小。从理论上分析了保偏光纤双折射色散对系统的影响。通过旋转半波片调节检偏器检偏角提高了系统测量灵敏度,通过优化检偏角,系统测量灵敏度为85 dB,最大空间分辨率为98 mm。 The distributed polarization-maintaining optical fiber stress sensing system is designed based on the PMF polarization coupling principle. Experiments were conducted on a 1050 m long polarization maintaining fiber to determine the system’s measurement sensitivity and spatial resolution. The relationship between coupling strength and stress and the influence of temperature on the system were tested. The experimental results show that the sensing system can detect polarization-maintaining optical fiber with a length of more than 1000 m. The measurement sensitivity and spatial resolution gradually decrease with the increase of optical fiber length. When the temperature is lower than 100 ℃, the fluctuation has little effect on the measurement. The influence of birefringence dispersion of PM fiber on the system is theoretically analyzed. By rotating the half-wave plate to adjust the analyzer angle, the system measurement sensitivity is improved. By optimizing the analyzer angle, the system has a measurement sensitivity of 85 dB and a maximum spatial resolution of 98 mm.