A drainage mechanism of a washing machine having an inner tub and an outer tub includes a water sealing cover, a lever structure and a driving device, a resistance arm end of the lever structure is connected with the water sealing cover, the driving device for driving the lever structure to work is arranged at an driving arm end of the lever structure, a drainage outlet is formed in a bottom wall of the inner tub, and the lever structure is driven by the driving device and drives the water sealing cover to close the drainage outlet in the washing and rinsing procedures and to open the drainage outlet in a draining procedure. The resistance arm end of the lever structure moves upwards and downwards to drive the water sealing cover to close and open the drainage outlet, thereby implementing drainage.