An alternating-current permanent magnet draining pump with reduced vibration noise, comprising: a pump cover; a pump body; a rotor assembly arranged inside the pump body and comprising a rotating shaft and a magnetic core disposed on the rotating shaft; and a stator assembly comprising a U-shaped stator core, a coil former and coils, wherein the coils wind around the coil former and the stator core is assembled to the coils, the stator assembly generating an alternating magnetic field to the magnetic core so as to drive it to rotate; wherein the pump body is formed by conducting an integrated injection molding on the stator assembly, wherein the pump body is configured to have a magnetic core accommodating space (10.1) for accommodating the magnetic core, wherein the magnetic core accommodating space has an opening at its top, and a supporting member is arranged in the opening to support a bearing of the rotating shaft; wherein the pump body comprises at least a first pump body portion formed by conducting a first shot of injection molding on the stator assembly to hermetically enclose the coils, and a second pump body portion formed by conducting a second shot of injection molding on the stator assembly and on the first pump body portion such that the first pump body portion and the second pump body portion combine into one, wherein the second pump body portion has a cylinder-shaped rotor housing and is provided with a connection portion for connecting to the pump cover, wherein a concave arc portion of the stator core is embedded within the second pump body portion, and wherein a part or an entirety of the inner arc surface of the concave arc portion together with an inner arc surface of the cylinder-shaped rotor housing surrounds and forms the magnetic core accommodating space (10.1). a pump cover; a pump body; a rotor assembly arranged inside the pump body and comprising a rotating shaft and a magnetic core disposed on the rotating shaft; and a stator assembly comprising a U-shaped stator core, a coil former and coils, wherein the coils wind around the coil former and the stator core is assembled to the coils, the stator assembly generating an alternating magnetic field to the magnetic core so as to drive it to rotate; wherein the pump body is formed by conducting an integrated injection molding on the stator assembly, wherein the pump body is configured to have a magnetic core accommodating space (10.1) for accommodating the magnetic core, wherein the magnetic core accommodating space has an opening at its top, and a supporting member is arranged in the opening to support a bearing of the rotating shaft; wherein the pump body comprises at least a first pump body portion formed by conducting a first shot of injection molding on the stator assembly to hermetically enclose the coils, and a second pump body portion formed by conducting a second shot of injection molding on the stator assembly and on the first pump body portion such that the first pump body portion and the second pump body portion combine into one, wherein the second pump body portion has a cylinder-shaped rotor housing and is provided with a connection portion for connecting to the pump cover, wherein a concave arc portion of the stator core is embedded within the second pump body portion, and wherein a part or an entirety of the inner arc surface of the concave arc portion together with an inner arc surface of the cylinder-shaped rotor housing surrounds and forms the magnetic core accommodating space (10.1).