The invention provides a miniature spiral arm tracking mechanical brake system of wind generators, belonging to the technical field of brake speed limit of wind generators, and comprising a brake component, a gyration transmission component, a pull rod, a vertical shaft, a steel wire rope and a gyrator, wherein the brake component is arranged at the rear end of a motor shaft of the generator, covered by the gyrator on the upper end of the vertical shaft and connected with the upper end of the pull rod which penetrates through the gyrator, the gyration transmission component on the vertical shaft is connected with the lower end of the pull rod and fixed with the upper end of the steel wire rope, while the lower end of the steel wire rope is fixed at the bottom of a support system. The brake component and gyration transmission component rotate with the gyrator according to the direction of wind, and the steel wire rope pulls the brake component by the gyrator transmission component and the pull rod to control the rotary speed of the wind generators within a certain range. The invention fills the gap of mechanical tracking control technology on the rotary speed of the miniature wind generators at home and abroad, effectively solves the problem of higher rotary speed of the wind generators with heavy wind, and has simple structure and low manufacture cost.