Abstract: A pressure adjustment mechanism of the sewing machine presser foot comprises a motor, a screw actuated by the motor, a spiral spring and a pressing plate for pressing against an upper end of the presser foot. A nut is screwed and connected on the screw, and the nut is lifted or lowered by the screw. The pressing plate is underneath the nut. The circumferential direction of the nut is unfixed. The spiral spring is located between the nut and the pressing plate, an upper end of the spiral spring is pressed against the nut, and a lower end of the spiral spring is pressed against the pressing plate. The spiral spring is being compressed under the effects of the nut and the pressing plate.