A rotor core lamination, wherein the rotor core lamination has an axial surface, the axial surface is provided with a first inner magnetic slot, a second inner magnetic slot, a first outer magnetic slot, and a second outer magnetic slot, the first inner magnetic slot has a first inner opening at the axial surface, the second inner magnetic slot has a second inner opening at the axial surface, an inner magnetic pole included angle Θ1 is formed between the first inner opening and the second inner opening, the inner magnetic pole included angle θ1 faces the outside of the rotor core lamination, the inner magnetic pole included angle Θ1 is an obtuse angle, the first outer magnetic slot has a first outer opening at the axial surface, the second outer magnetic slot has a second outer opening at the axial surface, the first outer opening and the second outer opening are both located in a region of the inner magnetic pole included angle θ1, an outer magnetic pole included angle Θ2 is formed between the first outer opening and the second outer opening, the outer magnetic pole included angle Θ2 faces the outside of the rotor core lamination, the outer magnetic pole included angle Θ2 is an obtuse angle greater than or equal to the inner magnetic pole included angle θ1, a difference between the outer magnetic pole included angle Θ2 and the inner magnetic pole included angle θ1 is in [0°, 50°], the first inner opening and the second inner opening are both spaced from the first outer opening and the second outer opening, and a width of the first inner opening is 1.5 times to 2 times a width of the first outer opening; wherein the rotor core lamination has a circumferential surface; characterized in that a partial region of the circumferential surface curves inward to form a plurality of concaves (C1, C2, C4, C5), each concave (C1, C2, C4, C5) has two opposite sides parallel to an axial direction, and the concave (C1, C2, C4, C5) penetrates through the axial surface at two opposite ends in the axial direction; a partial region of the circumferential surface protrudes to form a protrusion, the protrusion extends to the axial surface at the two opposite ends in the axial direction, the protrusion has two opposite sides parallel to the axial direction, said concaves are symmetrically distributed on two opposite sides of the protrusion, and said concaves (C1, C2, C4, C5) are spaced from the protrusion. the rotor core lamination has an axial surface, the axial surface is provided with a first inner magnetic slot, a second inner magnetic slot, a first outer magnetic slot, and a second outer magnetic slot, the first inner magnetic slot has a first inner opening at the axial surface, the second inner magnetic slot has a second inner opening at the axial surface, an inner magnetic pole included angle Θ1 is formed between the first inner opening and the second inner opening, the inner magnetic pole included angle θ1 faces the outside of the rotor core lamination, the inner magnetic pole included angle Θ1 is an obtuse angle, the first outer magnetic slot has a first outer opening at the axial surface, the second outer magnetic slot has a second outer opening at the axial surface, the first outer opening and the second outer opening are both located in a region of the inner magnetic pole included angle θ1, an outer magnetic pole included angle Θ2 is formed between the first outer opening and the second outer opening, the outer magnetic pole included angle Θ2 faces the outside of the rotor core lamination, the outer magnetic pole included angle Θ2 is an obtuse angle greater than or equal to the inner magnetic pole included angle θ1, a difference between the outer magnetic pole included angle Θ2 and the inner magnetic pole included angle θ1 is in [0°, 50°], the first inner opening and the second inner opening are both spaced from the first outer opening and the second outer opening, and a width of the first inner opening is 1.5 times to 2 times a width of the first outer opening; wherein the rotor core lamination has a circumferential surface; characterized in that a partial region of the circumferential surface curves inward to form a plurality of concaves (C1, C2, C4, C5), each concave (C1, C2, C4, C5) has two opposite sides parallel to an axial direction, and the concave (C1, C2, C4, C5) penetrates through the axial surface at two opposite ends in the axial direction; a partial region of the circumferential surface protrudes to form a protrusion, the protrusion extends to the axial surface at the two opposite ends in the axial direction, the protrusion has two opposite sides parallel to the axial direction, said concaves are symmetrically distributed on two opposite sides of the protrusion, and said concaves (C1, C2, C4, C5) are spaced from the protrusion.