Landslides occur frequently in China, often causing serious property losses and casualties. Therefore, scientific and effective landslide monitoring is of great significance for disaster prevention and mitigation. In recent decades, with the continuous development of monitoring technology, the level of landslide monitoring has been observably developed and improved in recent decades. It has gradually transferred from the past low-precision, point-type and manual monitoring to high-precision, distributed, and automated monitoring, which strongly supports the ability of governments at all levels from the national to the local level to cope with landslide disasters. In this paper, the current landslide monitoring methods and techniques are summarized and evaluated from four aspects: space (space satellite remote sensing), air (low altitude unmanned aerial vehicle remote sensing), ground (surface), and interior (inside the landslide body). The application method and effect of distributed optical fiber sensing technology in landslide monitoring are described, emphatically. The results show that the multi-source and multi-field monitoring inside the landslide body can obtain the multi-field information of the landslide, and the correlation model of the multi-field information can be established through further analysis, which can provide reliable data support for the evaluation and management of the landslide stability and has good research potential and application prospect. Finally, a new thinking of accurate and reliable monitoring, prediction and early warning of landslide deformation is proposed in this paper.