An inner drum , comprising lifting ribs , being provided in the inner drum and extending along a generatrix of the inner drum and water guide flow channels , wherein each of the lifting ribs is hollow inside, wherein a water-splashing surface of each of the lifting ribs is provided with permeable holes to allow a hollow part of the each of the lifting ribs to be communicated with an inside of the inner drum , and a rear end of each of the lifting ribs is provided with a water outlet structure, wherein an axis of the inner drum extends horizontally or is set to be inclined downwards gradually from front to back, wherein the water outlet structure arranged on the rear end of each of the lifting ribs is the permeable holes arranged on the rear end of each of the lifting ribs , and a notch arranged on a junction, being connected with a side wall of the inner drum of a washing machine, of the rear end of the lifting rib ; and insides of the lifting ribs are communicated with the inner drum via the permeable holes and the notch ; wherein one end of each of the water guide flow channels is arranged at the periphery of the inner drum bottom , characterized in that one end of each of the water guide flow channels is arranged at the periphery of the inner drum bottom in a manner of separating from the side wall of the inner drum by a gap, the notch is arranged at the junction of the rear end of each of the corresponding lifting rib being connected with the side wall of the inner drum of the washing machine, and the notch and the gap are arranged along a same generatrix of the inner drum in a manner of being close to each other such that washing water in the inner drum flows into the water guide flow channels through the gap. each of the lifting ribs is hollow inside, wherein a water-splashing surface of each of the lifting ribs is provided with permeable holes to allow a hollow part of the each of the lifting ribs to be communicated with an inside of the inner drum , and a rear end of each of the lifting ribs is provided with a water outlet structure, wherein an axis of the inner drum extends horizontally or is set to be inclined downwards gradually from front to back, wherein the water outlet structure arranged on the rear end of each of the lifting ribs is the permeable holes arranged on the rear end of each of the lifting ribs , and a notch arranged on a junction, being connected with a side wall of the inner drum of a washing machine, of the rear end of the lifting rib ; and insides of the lifting ribs are communicated with the inner drum via the permeable holes and the notch ; wherein one end of each of the water guide flow channels is arranged at the periphery of the inner drum bottom , characterized in that one end of each of the water guide flow channels is arranged at the periphery of the inner drum bottom in a manner of separating from the side wall of the inner drum by a gap, the notch is arranged at the junction of the rear end of each of the corresponding lifting rib being connected with the side wall of the inner drum of the washing machine, and the notch and the gap are arranged along a same generatrix of the inner drum in a manner of being close to each other such that washing water in the inner drum flows into the water guide flow channels through the gap. <EOS>