针对目前φ-OTDR光纤分布式振动传感器由于散射光波光强不稳定造成误报率较高的问题，文中提出一种φ-OTDR和Mach-Zehnder干涉仪相结合的光纤分布式振动传感新系统，φ-OTDR和Mach-Zehnder干涉仪分别对外界振动进行探测，从而降低单一φ-OTDR探测的误报率。实验研究了φ-OTDR和提出的新的复合结构系统对外界振动探测的误报率，实验结果表明：在复杂环境下，与现有φ-OTDR方案相比，提出的基于φ-OTDR和M-Z干涉仪复合结构的方案可以有效降低系统的误报率，使系统的误报率由单一φ-OTDR的25%降至2%。

A phase-sensitive optical time domain reflectometer(φ-OTDR) and Mach-Zehnder interferometer based fiber-optic distributed disturbance sensor was proposed in this paper. The aim is to obtain a low false alarm rate compared with current single φ-OTDR, which suffers from the high false rate due to the instability of scattering light intensity fluctuation in φ-OTDR. In the proposed sensor, φ-OTDR and Mach-Zehnder interferometer were multiplexed together. So, the φ-OTDR was used to detect and locate the disturbance, and the Mach-Zehnder interferometer was utilized to detect the disturbance, respectively. Then, the disturbance detected by φ-OTDR can be confirmed by the M-Z interferometer to realize a low false alarm rate due to the instability of φ-OTDR. The feasibility and effectivity of the proposed method by multiplexed φ-OTDR and Mach-Zehnder interferometer were validated in experiment, by comparing with current single φ-OTDR. It is found that the false alarm rate can be reduced to 2% from 25% by the single φ-OTDR.