Functional near-infrared spectroscopy (fNIRS), as an emerging brain imaging technique, has gradually become an important tool for stroke-related neurological function research due to its advantages of non-invasiveness, exercise tolerance, and portability. This article summarizes the application of fNIRS in evaluating neurological dysfunction, identifying functional injury sites, and monitoring rehabilitation outcomes, analyzes the advantages and disadvantages demonstrated in research and explores future improvement directions to promote further development of fNIRS in clinical applications.