A rotor structure, comprising: a rotor core on which a shaft hole connected to a rotary shaft and an even number of at least two magnet receiving grooves are formed along a rotation axis thereof, wherein the magnet receiving grooves are symmetrically distributed around a periphery of the shaft hole in the rotor core; magnets correspondingly installed in the magnet receiving grooves on a one-to-one basis; and wherein at least two first through grooves extending axially and depressed radially are symmetrically distributed and formed around an inner surface of the shaft hole on the rotor core, and first circulation holes are formed between the inner surface of the first through grooves and an outer surface of the rotary shaft; characterized in that six second circulation holes are symmetrically arranged at positions on the rotor core between the outer edge of the rotor core and the magnet receiving grooves correspondingly, the number of the magnet receiving grooves is also six, the second circulation holes extend along the axial direction of the rotor core and are radially distributed on the center line of the magnetic pole of the rotor; the size of the second circulation holes meets the followings: 2 ∗ δ ⩽ m ⩽ 4 ∗ δ, 8 ∗ δ ⩽ n ⩽ 14 ∗ δ, 2 ∗ δ ⩽ L ⩽ 4 ∗ δ; wherein δ is the width of an air gap between the stator and the rotor; m is a first distance between the outer edge of the second circulation hole and the outer edge of the rotor core along the radial direction of the rotor core; n is a second distance between the inner edge of the second circulation hole and the bottom of the edge of the side of the magnet receiving grooves away from the shaft hole along the radial direction of the rotor core; and L is the minimum width of the second circulation hole. a rotor core on which a shaft hole connected to a rotary shaft and an even number of at least two magnet receiving grooves are formed along a rotation axis thereof, wherein the magnet receiving grooves are symmetrically distributed around a periphery of the shaft hole in the rotor core; magnets correspondingly installed in the magnet receiving grooves on a one-to-one basis; and wherein at least two first through grooves extending axially and depressed radially are symmetrically distributed and formed around an inner surface of the shaft hole on the rotor core, and first circulation holes are formed between the inner surface of the first through grooves and an outer surface of the rotary shaft; characterized in that six second circulation holes are symmetrically arranged at positions on the rotor core between the outer edge of the rotor core and the magnet receiving grooves correspondingly, the number of the magnet receiving grooves is also six, the second circulation holes extend along the axial direction of the rotor core and are radially distributed on the center line of the magnetic pole of the rotor; the size of the second circulation holes meets the followings: 2 ∗ δ ⩽ m ⩽ 4 ∗ δ, 8 ∗ δ ⩽ n ⩽ 14 ∗ δ, 2 ∗ δ ⩽ L ⩽ 4 ∗ δ; wherein δ is the width of an air gap between the stator and the rotor; m is a first distance between the outer edge of the second circulation hole and the outer edge of the rotor core along the radial direction of the rotor core; n is a second distance between the inner edge of the second circulation hole and the bottom of the edge of the side of the magnet receiving grooves away from the shaft hole along the radial direction of the rotor core; and L is the minimum width of the second circulation hole.