A drum washing machine, a door (17) is installed at the front opening (16) of the drum washing machine, and one side of the door (17) is hinged with a case of the washing machine. The door is an inner and outer double-layer structure, comprising an inner door (1) and an outer door (2). The inner door (1) is hinged with the case of the washing machine to partially open/close the front opening (16) of the case. An opening (8) is provided at an upper part of the inner door, and the outer door is hinged with the inner door (1) to open/close the opening at upper part of the inner door (1). The inner door (1) and the outer door (2) cooperate to fully open/close the front opening (16) of the case. Normally, the user can open the inner door (1) to pick/place laundry from/in the washing machine. If the user wants to add laundry or detergent to the washing machine during the washing process, the water inside the washing machine did not need to be completely discharged before the door is open. Just open the outer door (
