结构健康监测、医疗诊断分析、气压检测以及**工程应用等领域对压力的高灵敏度探测要求越来越高。光纤传感器由于其体积小、灵敏度高及抗电磁干扰等优点被广泛应用于压力测量。针对石英材料的杨氏模量较高，传统实芯光纤压力传感器的受压变形量较小，导致测量灵敏度很难提高。文章提出了一种基于游标效应的双Sagnac干涉环式光纤压力传感器。传感器由保偏光子晶体光纤(Polarization Maintaining Fiber, PM-PCF)作为敏感单元实现Sagnac干涉并通过不同PCF长度实现针对压力增敏特性的游标效应。传感器分别采用在单模光纤中嵌入PM-PCF形成传感器的参考单元和压力敏感单元，并对Sagnac环的感压部分进行封装，通过实验对并联型Sagnac环压力传感器的压力特性进行研究。实验结果表明在压力范围为0~2.4MPa内，压力传感器最大灵敏度为-54.491nm/MPa，分辨率为0.367kPa。相比无游标效应的Sagnac环压力传感器，其压力灵敏度放大了16.7倍。此外，传感器具有制造简单、结构坚固、运行稳定的优点，为高灵敏度压力传感器提供了一种替代设计方案。

A double Sangac interference ring optical fiber pressure sensor based on vernier effect is proposed. The sensor uses polarization maintaining photonic crystal fiber (PM-PCF) as a sensitive unit to realize Sagnac interference and vernier effect for pressure sensitivity through different PCF lengths. The sensor uses PM-PCF embedded in the single-mode optical fiber to form the reference unit and pressure sensitive unit of the sensor, and the pressure sensing part of the Sagnac ring is packaged. The pressure characteristics of the parallel Sagnac ring pressure sensor are studied through experiments. The experimental results show that the maximum sensitivity of the pressure sensor is -54.491nm/MPa and the resolution is 0.367kPa in the pressure range of 0~2.4MPa. Compared with the Sagnac ring pressure sensor without vernier effect, its pressure sensitivity is amplified by 16.7 times. In addition, the sensor has the advantages of simple manufacture, solid structure and stable operation, which provides an alternative design scheme for the high-sensitivity pressure sensor.