The realtime acoustic emission monitoring system for grinder was designed to overcome the questions which included the lack of integrated intelligent realtime monitoring and the problem of slower response velocity of current monitoring modes in China. In the system, processors of S3C2416, TMS320F28335 were taken as the core by which the realtime acoustic emission signals of grinder were collected and displayed, and the characteristic frequency of singular point of the signals was calculated. The dynamic control to grinding machine was finished by the way of setting the threshold value of the characteristic frequency energy. The system has the advantages of strong compatibility, small size and higher stability which can be configured with the CNC grinding machine quickly and then meets the processing requirements of high efficiency grinding machine.