Background　Near-infrared spectroscopy （NIRS） can detect the regional cerebral oxygen saturation （rSO2） penetrating the extra-cranial organization， which has such features as of being non-invasive， continuous and real-time.　Objective　The paper reviews the research progress of the application of NIRS technology to brain function monitoring in the adult cardiac surgery， and provide practical guidance for clinical anesthetists.　Content　From the aspects of prognostic evaluation， intraoperative intervention guidance and preoperative risk stratification， we reviewed recent case reports， observation studies and experimental studies， as well as existing dispute and its possible reasons.　Trend　NIRS has broad application prospects in cardiac surgery perioperative monitoring， while in terms of specific clinical guidance， more high-level evidences are needed.