Inclusion Criteria:  ASA II-III; No cognitive impairment was assessed one day before surgery; Patients undergoing elective CPB cardiac surgery(valvular heart surgery and coronary bypass surgery) and signed informed consent.  Exclusion Criteria:  Non-CPB surgery, macrovascular surgery, heart transplantation, correction of congenital heart disease; Stroke, schizophrenia, depression, Parkinson's disease, epilepsy or dementia; Inability to communicate with language impairment or major hearing or visual impairment; Liver function child-pugh Grade C, severe liver dysfunction; Severe renal insufficiency requires preoperative renal replacement therapy; A past history of intraoperative knowledge.