A motor stator, comprising a stator core and a winding, wherein the stator core is cylinder-shaped and comprises an inner wall and a plurality of stator slots disposed on the inner wall, the plurality of stator slots are evenly distributed in a circumferential direction of the inner wall, and every three adjacent stator slots form a stator slot group; in a radial direction of the stator core, a plurality of wire slots are arranged in each stator slot, and radius sizes between a circle center of the stator core and the wire slots in each stator slot are different; and in a circumferential direction of the stator core, wire slots with a same radius size in the stator slots form a wire slot layer; the winding comprises a three-phase winding, the three-phase winding is sequentially and alternatively wound in different stator slot groups in the circumferential direction of the stator core, and the three-phase winding is further sequentially wound in wire slot layers; and each phase winding comprises at least one branch, the at least one branch comprises a plurality of U-shaped wires connected in series, each U-shaped wire comprises a bending end, a welding end is formed between two U-shaped wires connected in series, and the bending end and the welding end are alternately connected between the stator slot groups, and are also alternately connected between the wire slot layers; and ends connected between same two adjacent wire slot layers all are bending ends of the U-shaped wires or all are welding ends between the U-shaped wires, and characterized in that the bending ends connected between the same two adjacent wire slot layers have a same shape and a same span, and the welding ends connected between the same two adjacent wire slot layers have both a same span and a same twisting angle. the stator core is cylinder-shaped and comprises an inner wall and a plurality of stator slots disposed on the inner wall, the plurality of stator slots are evenly distributed in a circumferential direction of the inner wall, and every three adjacent stator slots form a stator slot group; in a radial direction of the stator core, a plurality of wire slots are arranged in each stator slot, and radius sizes between a circle center of the stator core and the wire slots in each stator slot are different; and in a circumferential direction of the stator core, wire slots with a same radius size in the stator slots form a wire slot layer; the winding comprises a three-phase winding, the three-phase winding is sequentially and alternatively wound in different stator slot groups in the circumferential direction of the stator core, and the three-phase winding is further sequentially wound in wire slot layers; and each phase winding comprises at least one branch, the at least one branch comprises a plurality of U-shaped wires connected in series, each U-shaped wire comprises a bending end, a welding end is formed between two U-shaped wires connected in series, and the bending end and the welding end are alternately connected between the stator slot groups, and are also alternately connected between the wire slot layers; and ends connected between same two adjacent wire slot layers all are bending ends of the U-shaped wires or all are welding ends between the U-shaped wires, and characterized in that the bending ends connected between the same two adjacent wire slot layers have a same shape and a same span, and the welding ends connected between the same two adjacent wire slot layers have both a same span and a same twisting angle.