The invention discloses a powder mixing machine for preparing magnets by means of powder metallurgy method. The powder mixing machine comprises a machine seat rack; the machine seat rack is provided with a powder mixing box, a discharge chute, a fixed plate, a drive motor, a rotating shaft of the motor, a feeding hole and a mixing motor; the powder mixing box is fixedly connected with the upper end of the machine seat rack; the discharge chute is fixedly connected with the bottom of the powder mixing box; the fixed plate is fixedly connected with the left end of the powder mixing box; the drive motor is fixedly connected with the upper end of the fixed plate; the rotating shaft of the motor is movably connected with the right end of the drive motor; the feeding hole is formed at the left upper part of the powder mixing box; the mixing motor is fixedly connected with the middle of the upper end of the powder mixing box. Powder shovel blades are additionally arranged, so that powder at the bottom of the powder mixing box can be effectively scooped up; then, secondary mixing is performed, so that the powder mixing uniformity is enhanced, the powder is prevented from adhering to the bottom of the mixing box, so that the powder mixing efficiency is improved.