Abstract: Distributed fiber-optic seismic sensing is a next-generation seismic acquisition technology. It records dynamic strain based on the phase change of back-scattered Rayleigh light caused by incident seismic waves. This method generates a dense record of the seismic wavefield using optic fibers which are durable in extreme environments and have low maintenance costs. Consequently, it has been widely used for surveys of urban areas, the ocean bottom, boreholes, and glaciers. In this study, we focus on its applications in seismic imaging and the monitoring of seismic velocity change. Previous studies have employed both passive and active sources to explore structures ranging from near-surface depths to the Moho. Although impressive achievements have been made, the research community still faces challenges such as data quality, signal fidelity, storage, processing, and information mining of large data volumes. Therefore, active and passive high-resolution 4D imaging, instrument transfer function calculation, and effective big data mining should be conducted as part of future studies to achieve high-density and high-precision seismic imaging with this fiber-optic sensing technology.