Paper shredder with constant paper shredding speed

The utility model relates to a paper shredder, in particular to a paper shredder with a constant paper shredding speed. The paper shredder with the constant paper shredding speed comprises a signal processing circuit and a motor, and also comprises a speed testing circuit for detecting the rotating speed of the motor and a silicon controlled drive circuit for regulating the voltage of the motor, wherein the speed testing circuit is connected with the signal processing circuit, and the silicon controlled drive circuit is respectively connected with the signal processing circuit and the motor. The silicone controlled drive circuit is adopted in the paper shredder, and the voltage of the motor is regulated according to the motor speed signal, therefore the power is regulated so that the rotating speed of the motor is better controlled; and the rotating speed is controlled according to the actual requirement so as to be stable, the motor speed is not high when a small amount of paper is shredded, and thus the noi