The invention discloses a stator assembly and a winding method thereof. The stator assembly comprises a strip-shaped stator core, three-phase coil windings and end insulation, wherein the strip-shapedstator core is used for numbering and sequencing each stator core unit from 1 to 12 and from left to right in the direction that the front surface of the inner cambered surface faces outwards; the three-phase coil windings comprise a U-phase winding, a V-phase winding and a W-phase winding, the upper end insulation of the third stator core unit, the fourth stator core unit and the fifth stator core unit is respectively provided with a first incoming line contact pin, a second incoming line contact pin and a third incoming line contact pin which can be used for winding U-phase, V-phase and W-phase windings into a line, and the upper end insulation of the tenth stator core unit is provided with a three-phase winding main outgoing line contact pin; and the first incoming line contact pin, the second incoming line contact pin and the third incoming line contact pin are respectively wound on the corresponding stator core units, and finally the three-phase coil winding is uniformly led outby the main outgoing line contact pin of the tenth stator core unit. The stator assembly has the advantages of reasonable layout, convenient winding, convenient wiring and low error rate.