Laser speckle contrast imaging (LSCI) is a powerful and simple non-scanning real-time hemodynamic imaging method, with the advantages of high spatial and temporal resolution, wide imaging field, high-speed imaging, low damage, relatively simple instrument structure. After decades of development, it already has had the ability to quantify flow changes with higher resolution. Although LSCI is limited to superficial tissue imaging due to the limitation of depth resolution, it has been playing an important role in the studies and clinical applications of biomedical fields such as dermatology and neurological disease research. This paper briefly introduces the basic principle, typical device and technical progress of LSCI, and reviews the recent progress in brain diseases such as stroke, drug addiction, Alzheimer's disease and other applications of brain science. Finally, we discuss the prospects for development of LSCI in the study of brain science.