A washing machine comprises: a washing drum, a circulating water pipeline, a drainage pipeline, and a membrane module. The membrane module is provided with a water inlet, a water production outlet, and a sewage outlet; the membrane module is connected to the drainage pipeline by means of the sewage outlet; the membrane module is also provided with a flushing inlet through which water can enter for cleaning the membrane module; and the flushing inlet is communicated with the water inlet of the washing machine. A maintenance method for the water purification device comprises: a water purification device receives a water-purifying command; control washing water to enter a membrane module; and the water purification device stops water purification after running for a cycle, and controls the washing water to enter the membrane module.
