Postoperative stroke following cardiac surgery is associated with a ninefold increase in mortality risk compared to patients without stroke. Perioperative monitoring in cardiac surgery involves a range of complex and diverse techniques, presenting significant challenges for anesthetic management. Multimodal brain monitoring technology offers a novel approach to cerebral protection during the perioperative period of cardiac surgery by integrating hemodynamic parameters, autonomic nervous responses, cerebral oxygen saturation and indices, electroencephalographic activity, and cerebral blood flow velocity. Therefore, this study aims to evaluate the comprehensive early-warning efficacy of multimodal brain monitoring for perioperative stroke in cardiac surgery patients, determine the cumulative incidence of perioperative stroke-including covert stroke-and provide a new theoretical basis for optimizing cerebral protection strategies in cardiac surgery.