A washing machine including: a first drainage pump arranged between a washing drum and a filter membrane assembly. The first drainage pump pumps water in the washing drum into the filter membrane assembly for filtration and ensures that a water level in a water inlet cavity of the filter membrane assembly is not higher than a lower edge of a sewage outlet, so as to prevent reduce of the amount of washing water due to drainage of excessive washing water/rinsing water. Since the first drainage pump is a low-lift water pump, water in the filter membrane assembly moves continuously during filtration, so as to scour pollutants on a surface of a filter membrane/membrane filament, reduce an accumulation degree of the pollutants, effectively prevent blockage and achieve low noise.
