Brain computer interface(BCI)is a rapidly developing rehabilitation technology in recent years, which has been gradually used for cognitive rehabilitation of stroke patients.BCI can activate brain regions related to cognition to a greater extent through motor imagery and neural feedback technology, promote functional connectivity between brain regions, and ameliorate cognitive impairment after stroke.This paper summarized the mechanisms involved in BCI promoting cognitive rehabilitation and current applications of BCI in post-stroke cognitive impairment, and identifies the shortcomings of BCI in the treatment of post-stroke cognitive impairment, in order to provide insight for the research and clinical practice of BCI in post-stroke cognitive rehabilitation.