The inner tub of a washing machine comprises a tub body, a balancing ring at the upper part of the tub body and a tub bottom at the lower part of the tub body. An annular necking structure, whose inside diameter is smaller than that of the tub body, is arranged on the tub body and positioned below the balancing ring, a plurality of dewatering holes are distributed at the necking structure and/or between the necking structure and the balancing ring. A disconnected type filtering cover on the internal wall of the tub body and positioned below the necking structure comprises a main body and an auxiliary block, the auxiliary block is arranged above the main body and below the necking structure and is located at the upper part of the inner tub, and a water passing gap is arranged between the auxiliary block and the main body.