Abstract: The World Health Organization lists fine particulate matter (PM_2.5) as one of the ten threats to global health. In recent years, the impact of PM_2.5 pollution on stroke has become a new focus. This article reviewed the epidemiological studies on PM_2.5 exposure and stroke, and discussed the new biological mechanisms that PM_2.5 exposure may trigger or induce the occurrence and development of stroke, including PM_2.5 translocation, autonomic dysfunction, gluconeogenesis, and epigenetic mechanisms. The factors affecting PM_2.5 exposure and stroke occurrence were summarized. It was proposed to establish an early warning mechanism for the incidence and death of high-risk stroke groups, aiming to provide reference for the primary prevention and control of stroke and air pollution control in China.