Disclosed is a washing machine, a housing (2) of the washing machine being provided therein with an inner drum (1); the inner drum (1) is provided thereon with a drain port (23), and a drain valve (24) is mounted at the drain port (23); the washing machine is further provided thereon with a positioning and locking mechanism for rotating the inner drum (1) to a fixed drainage position and fixing the inner drum; the washing machine is provided thereon with a spool opening mechanism that opens the drain valve (24) after the inner drum (1) is rotated to the fixed drainage position, such that when the washing machine is to be drained, the drain valve (24) is opened after the inner drum (1) is rotated to the fixed drainage position so as to discharge the washing water in the inner drum (1); the inner drum is a conical drum having a small diameter at one end and a large diameter at the other end; the larger end of the inner drum (1) is provided with a de-watering flow passage (36); one end of the de-watering flow pa
