The invention discloses a permanent magnet force regulator, comprising a permanent magnet base, a spring supporting frame, a motor supporting frame, a spring, a motor and pure iron sheets; the spring supporting frame and the motor supporting frame are respectively arranged at the two ends of the permanent magnet base; two installation holes are arranged on the permanent magnet base; there are multiple pure iron sheets; the pure iron sheets are welded on the spring at equal distances through a side; a spring installation hole is arranged on the motor supporting frame; a spring installation axle is arranged on the spring supporting frame; two ends of the spring are respectively fixed on the spring installation axle and in the spring installation hole; the motor is fixed on the motor supporting frame through bolts; the motor is equipped with a through axle; the through axle penetrates the spring installation hole and resists against the pure iron sheet welded at the end part of the spring; the spring is in compressed state under the restriction of the through axle and the spring supporting frame. According to the invention, the output permanent magnetic force is controllable; the power consumption of the permanent magnet force regulator is relatively low; and heat deformation is avoided through low heat production.