The research of EEG signals can not only improve people's cognition to the brain, but also build a new way to communicate with the outside world of the brain. This article starts from the characteristics of motor imagery EEG signals. Firstly the paper makes a summary about the developments of analysis and processing algorithms for motor imagery EEG signals in recent years. Secondly, the advantages, shortages and applicable condition for the common used processing algorithms in EEG feature extraction and recognition are analyzed emphatically. Finally, the current problems existing in the EEG processing algorithms are summarized and the directions for further research are also discussed.