The invention relates the microscopic cutting device. The invention overcomes the defects of strong working strength, fatigability and big personal error. The device comprises computer 1, microscope 2, CCD cam 3, free mechanical micro motion desk 4, clamp 5, ultrasonic vibration emitter 6, cutting needle 7, biological section stage 8 and cutter bar. 2 is installed under 8, 3 is connected with 2 to collect the object magnified by 2, the signal output terminal of 3 is connected with signal input terminal of 1, 4 is installed at the side of 8, the signal output terminal of 1 is connected with controlling terminal of 4, 5 is fixed on the 4, 11 is fixed on the 5, one end of 11 is connected with one end of 6, the other end of 6 is connected with the butt of 7, the tip of 7 extends to the upper surface of 8, and the other signal output terminal of 1 is connected with the input terminal of 6.