Depth of anesthesia (DOA) monitoring is extremely important in improving the quality of anesthesia, ensuring patient’s safety and rehabilitation in operation. Electroencephalogram (EEG) signal analysis algorithms are reviewed systematically. The application research and development state of these parameters algorithms such as bispectral index scale (BIS), nacrotrend (NT) and cerebral state index (CSI) in DOA monitoring process are introduced. Firstly, the advantages and disadvantages of EEG analysis algorithms of these parameters in clinical application are compared. Secondly, the sort entropy index (SEI) algorithm with excellent de-nosing capability is proposed. And the back propagation (BP) neural network is used to revise and optimize BIS, NT and SEI to implement DOA monitoring more accurately. Finally, the applications in DOA monitoring field are forecasted.