The disclosure relates to a draining structure of a washing machine. An inner drum is installed in a washing machine housing, a drain port is arranged on the inner drum, and a drain valve is installed at the drain port; the washing machine is further provided with a positioning and locking mechanism for making the inner drum rotate to a fixed drainage position and be locked; and the washing machine is provided with a valve core opening mechanism for opening the drain valve after the inner drum rotates to the fixed drainage position, so that when the washing machine is in a draining state, the drain valve is opened after the inner drum rotates to the fixed drainage position to discharge the washing water in the inner drum. In this way, the drain valve is in a closed state under the normal state of the washing machine, and is in an open state under the joint action of the positioning and locking mechanism and the valve core opening mechanism when the washing machine is in a draining state, so that the effect that during the rotating process of the inner drum, the inner drum is sealed, and during drainage, the drain valve is opened to allow water in the inner drum to be discharged normally is realized; besides, the inner drum does not have to be sleeved with an outer drum, thus increasing the volume of the inner drum and improving the washing capacity of the washing machine.