The invention discloses a low-power-consumption high-speed double-ring magnetic steel brushless direct current motor. The motor comprises a rotor system and a stator system. The rotor system includes:an outer mounting sleeve, an outer magnetic conductive ring, outer parallel magnetizing magnetic steel, outer upper 45-degree magnetizing magnetic steel, outer lower 45-degree magnetizing magnetic steel, an outer magnetic steel lock nut, an outer assembly lock nut, a rotor shell, an inner mounting sleeve, an inner magnetic conductive ring, inner parallel magnetizing magnetic steel, inner upper 45-degree magnetizing magnetic steel, inner lower 45-degree magnetizing magnetic steel, an inner magnetic steel sheath, an inner magnetic steel lock nut and an inner assembly lock nut; the stator systemcomprises a hollow cup stator framework, a stator aluminum substrate, a winding and epoxy resin glue. According to the invention, a double-ring axial Halbach magnetic steel structure without a statorcore is adopted, magnetic hysteresis loss caused by a fixed iron core and torque pulsation caused by tooth grooves are eliminated, eddy current loss is reduced, the upper portion and the lower portion of the inner-ring magnetic steel and the lower portion of the outer-ring magnetic steel are each provided with a 45-degree magnetized magnetic steel, the magnetic circuit magnetism gathering effectis achieved, the air gap flux density is increased, the air gap flux density flat top width is widened, and the output torque and the output torque precision are improved.