The invention discloses a permanent magnet brushless motor comprising a rotor with a dustproof structure, comprising a housing (3), a stator, a permanent magnet rotor (4), a rotor shaft (5), a cooling fan (14), and an end cap (17). The housing (3) is provided with an air inlet (8) and an air inlet (15). The stator includes a stator core (1) and an electromagnetic winding (2). The air inlet (8) side of the housing (3) is provided with a dust cover (7), and the dust cover (7) faces the end face of the stator core (1). The stator core (1) is provided with an isolating slot wedge (10) matched with openings of electromagnetic winding slots (11), and the isolating slot wedge (10) is made of insulating material. The isolating slot wedge (10) and the dust cover (7) are mutually sheathed, and the isolating slot wedge (10) and the teeth of all the electromagnetic winding slots (11) constitute a closed stator inner circle. By adopting the structure, the permanent magnet brushless motor of the invention has the advantages of simple and reasonable structure, convenient installation, good sealing performance of the rotor, capability of avoiding iron powder and iron filings adsorption on the surface of the permanent magnet rotor (4), long service life, and the like.