The invention discloses a grinding wheel grinding sound emission monitoring device, and relates to a sound emission monitoring device. The grinding wheel grinding sound emission monitoring device comprises a locking flange, a magnetic rotation shaft, a shell, an annular magnetic pole, a permanent magnet, a magnetic slide plate, a limited block, an annular conical surface magnetic pole, a bevel gear, a handle, a retainer ring, a plug, an end cover, magnetorheological fluids, a sound emission sensor seat, a sound emission sensor and a detection circuit, the locking flange is locked with an external grinder grinding wheel, the left end of the magnetic rotation shaft is connected with the locking flange, the magnetic rotation shaft is provided with a hollow hole, the plug is arranged at an opening end of the hollow hole, the magnetorheological fluids are stored in the hollow hole, the hollow hole is communicated with the outer surface of the magnetic rotation shaft, the shell is sleeved on the magnetic rotation shaft, both the annular magnetic pole and the annular conical surface magnetic pole are positioned in the shell and are sleeved on the magnetic rotation shaft, the left end of the annular conical surface magnetic pole is connected with the magnetic slide plate, the left end of the magnetic slide plate is connected with the permanent magnet in a threaded manner, the right end of the annular conical surface magnetic pole is meshed with the bevel gear, and the detection circuit is arranged outside the shell and is electrically connected with the sound emission sensor.