The invention discloses an efficient electromagnetic brake. The efficient electromagnetic brake comprises a motor, and a first rotating shaft which is fixedly mounted on an output shaft of the motor through a coupler, wherein brake discs are movably mounted at the top side and the bottom side of the first rotating shaft; mounting slots are formed in the top side and the bottom side of the first rotating shaft; the sides, close to each other, of the two brake discs correspondingly extend into the two mounting slots; U-shaped slots are formed in two sides of the brake discs, and U-shaped rods are movably mounted in the two U-shaped slots; fixing slots are formed in two inner sidewalls of the mounting slots; and the top ends of the two U-shaped rods correspondingly extend into the two fixingslots. According to the efficient electromagnetic brake, the brake discs can be conveniently mounted and dismounted, so that the electromagnetic brake can be conveniently maintained and replaced, andthe efficient braking performance is ensured; and meanwhile, two electromagnetic brake bodies can be conveniently mounted on motors with different size, so that the generality is improved, and the convenience and efficiency of use are improved.