The invention discloses a permanent magnet brushless direct-current motor rotor, which comprises a rotor core and a plurality of permanent magnets, wherein the permanent magnets are uniformly distributed on the outer side of the rotor core; the rotor core comprises a core body, a plurality of salient poles are uniformly distributed along the circumference on the outer edge of the core body and the salient poles are used for conducting magnetism and synthesizing magnetic poles; the permanent magnets and the salient poles are arranged at intervals; the polarity of the salient poles and the permanent magnets is the same; the permanent magnets are crescent and the radius of the outer circular arcs of the permanent magnets is smaller than the radius of the inner circular arcs of the permanent magnets; the inner circular arcs of the permanent magnets are matched with the outer edge of the core body of the rotor core. The permanent magnet brushless direct-current motor rotor has the advantages that the used materials are fewer, the performance and the efficiency are high and the requirements on environmental protection and energy saving in the motor industry can be met.