A stator applied in an electrical motor, the stator comprising: a hollow iron core, having two axially opposite surfaces (111, 112) and a plurality of accommodating spaces communicated with the surfaces (111, 112), the accommodating spaces being arranged in an annular pattern; and a plurality of coil windings, each of the coil windings comprising a plurality of wires wound via the accommodating spaces, portions of the wires of the coil windings located in the accommodating spaces being radially concentrically arranged to form a plurality of winding layers, wherein in at least one of the accommodating spaces, a wire cross-sectional area of the wire of the radially innermost one of the winding layers is smaller than a wire cross-sectional area of the wire of the outermost one of the winding layers, first, second, third, fourth, fifth and sixth winding layers (121a, 121b, 121c, 121d, 121e, 121f) of the winding layers are arranged from a radially outer side to a radially inner side, respectively, of the hollow iron core, the coil windings comprise a first coil winding, a second coil winding, and a third coil winding, the first coil winding is constituted by the first and second layers (121a, 121b) of the winding layers, the second coil winding is constituted by the third and fifth layers (121c, 121e) of the winding layers, and the third coil winding is constituted by the fourth and sixth layers (121d, 121f) of the winding layers, and wires (122c, 122d) of the third and fourth winding layers (121c, 121d) of the winding layers are connected in parallel, and wires (122e, 122f) of the fifth and sixth layers (121e, 121f) of the winding layers are connected in parallel. a hollow iron core, having two axially opposite surfaces (111, 112) and a plurality of accommodating spaces communicated with the surfaces (111, 112), the accommodating spaces being arranged in an annular pattern; and a plurality of coil windings, each of the coil windings comprising a plurality of wires wound via the accommodating spaces, portions of the wires of the coil windings located in the accommodating spaces being radially concentrically arranged to form a plurality of winding layers, wherein in at least one of the accommodating spaces, a wire cross-sectional area of the wire of the radially innermost one of the winding layers is smaller than a wire cross-sectional area of the wire of the outermost one of the winding layers, first, second, third, fourth, fifth and sixth winding layers (121a, 121b, 121c, 121d, 121e, 121f) of the winding layers are arranged from a radially outer side to a radially inner side, respectively, of the hollow iron core, the coil windings comprise a first coil winding, a second coil winding, and a third coil winding, the first coil winding is constituted by the first and second layers (121a, 121b) of the winding layers, the second coil winding is constituted by the third and fifth layers (121c, 121e) of the winding layers, and the third coil winding is constituted by the fourth and sixth layers (121d, 121f) of the winding layers, and wires (122c, 122d) of the third and fourth winding layers (121c, 121d) of the winding layers are connected in parallel, and wires (122e, 122f) of the fifth and sixth layers (121e, 121f) of the winding layers are connected in parallel.