Stroke, as an acute cerebrovascular disease, is characterised by high morbidity, recurrence, disability, mortality and heavy economic burden, posing an extremely serious threat to human life and health. As a non-invasive, portable and anti-electromagnetic interference brain optical imaging method, functional near-infrared spectroscopy (fNIRS) has been widely used in neuroscience and clinical rehabilitation in recent years. Especially in the neurological rehabilitation of stroke, fNIRS provides a powerful support for rehabilitation assessment, treatment optimisation and neural mechanism research with its unique advantages. In this paper, we will review the main application directions and research progress of fNIRS in this field, the controversies, and the future research directions, aiming to provide a reference for the research and practice of neurological rehabilitation in stroke.