目前，隧道的安全服役离不开安全监测和预警，分布式光纤技术为隧道的安全运营提供一种全新的技术保障手段。为解决隧道的差异性沉降监测难题，从实验室内光纤轴向拉伸监测变形和Z字形布线方式监测差异沉降的原理及其在某隧道内的应用效果2个方面，阐述分布式光纤监测技术在隧道工程中的应用。无论室内的等级光纤拉伸和还是Z字形布线方式，位移和应变的对应关系都呈现出良好的线性比例关系，为工程实际应用提供理论依据。从工程监测结果来看，分布式定点应变感测光缆能实现对管片接缝变形的准确定位和毫米级接缝宽度感知，Z字形光缆布设方式也能对隧道内管片差异沉降实现精准感知，充分体现分布式光纤监测技术在隧道结构健康监测中的鲜明优势。

 At present, the safe service of tunnel is still inseparable from safety monitoring and early warning, hence, the distributed optical fiber technology can provide a brand new technical guarantee for the safe operation of tunnel. In order to solve the difficulties of differential settlement monitoring in tunnel, the application of distributed optical fiber monitoring technology in tunnel engineering is expounded from two aspects, i.e. fiber axial tensile deformation monitoring in laboratory and principle of monitoring differential settlement in Zshaped wiring mode and its application effect in a tunnel. Regardless of the laboratory grade fiber stretching and the Zshaped wiring, the corresponding relationship between displacement and strain shows a good linear proportional relationship, which provides theoretical basis for practical engineering applications. The monitoring results show that the accurate positioning of segment seam deformation and millimeterlevel seam width sensing can be realized by the distributed fixedpoint strainsensing cable, and the accurate perception of the differential settlement of the tubes in the tunnel can be realized by Zshaped optical cable layout, which fully reflects the distinct advantages of distributed optical fiber monitoring technology in tunnel structural health monitoring.