Abstract: In acoustic emission (AE) experiment on high speed deep grinding cemented carbide PA30, which is a hard difficult-to-machine material, the root-mean-square characteristic parameters of acoustic emission signal (AE_RMS) and grinding force increase as the workpiece speed and the depth of cut increase, while they decrease as the wheel speed increase.Therefore, the grinding force and the AE_RMS have the same change tendency.The spectrum energy of the acoustic emission signal when high speed deep grinding cemented carbide PA30 is focused on 100~600kHz spectral ranges.The energy and frequency range of the AE signal spectrum are larger than that in low speed shallow grinding.