The utility model relates to a square-wave three-phase permanent-magnet brushless DC motor, aiming at solving the problems on current square-wave permanent-magnet motors and permanent-magnet sine motors. The number of the magnetic poles of the rotor core of the utility model 2P is equal to 8, and the number of the slots of a stator core Z is equal to 12; correspondingly, 12 teeth are provided, including three big teeth, three middle teeth and six small teeth; the mechanical angles of the three types of teeth are respectively 50 degrees plus or minus 5degrees, 40 degrees plus or minus 5degrees, and 15 degrees plus or minus 5 degrees, and the total mechanical angle of one big tooth, one middle tooth and one small tooth is 120 degrees. Three-phase concentrated windings are mainly wounded on the big teeth and the middle teeth, each phase is provided with only two concentrated windings and the three-phase motor only has 6 concentrated windings. When driven with three-phase square-wave current, the motor generates smooth moment with the fluctuation index approximately the same with that of a permanent magnet sine servo motor; meanwhile the ends of the windings of the square-wave three-phase permanent-magnet brushless DC motor are minimized in size, the air gap is minimized, material consumption is reduced to the lowest, the position moment is reduced to the lowest and waste is reduced to the lowest.