相位敏感光时域反射计(φ-OTDR)因其优良的综合性能成为目前最主要的入侵和振动分布式传感监测方法之一。总结了φ-OTDR分布式光纤传感监测系统的光源技术、传感头技术和信号解调技术的研究进展，对各部分的最新研究成果进行了评述，对其创新性和存在的问题进行了分析。阐述了微分振幅检波技术和直接相位解调技术的工作原理，并对两种解调方法进行了比较：微分振幅检波技术从散斑图样来解调相位信息是艰难的，它是一种非直接的、定性的测量方法；直接相位解调技术是一种直接的、定量的测量方法，可以应用于动态测量以及光纤水听器中，但受相干散斑衰落的影响较大。最后展望了基于φ-OTDR的分布式光纤传感监测技术的应用前景。

Phase-sensitive optical time domain reflectometer φ-OTDR is one of the most important means of distributed sensing and monitoring for intrusion and vibration due to its excellent overall performance. This paper explains the research progress of the source technology, the sensing technology and the signal demodulation technology of the distributed optical fiber sensing and monitoring system based on φ-OTDR, reviews the newest research results, and analyzes their innovativeness and existing problems. The principles of differential amplitude detection and direct phase demodulation are explained, and the difference between these two kinds of demodulated methods are compared. It is hard to demodulate the phase signal only from the speckle using differential amplitude detection, and this scheme is just an indirectly and qualitatively measuring method. Direct phase demodulation is a directly and quantitatively measure method, and can be use in dynamic measurement or fiber hydrophone, etc., but the influence of fading noise resulting from the inner pulse interference of Rayleigh scattering beams is obvious. Finally, the prospect of distributed optical fiber sensing and monitoring technology based on φ-OTDR is set forth.