Water cup assembly, drainage system and dish washing machine

The invention relates to the technical field of household appliances, and particularly relates to a water cup assembly, a drainage system and a dish washing machine. The water cup assembly comprises awater cup, a residual water drainage structure and a negative pressure device, wherein a drainage cavity is formed in the water cup; a residual water cavity is formed in the residual water drainage structure, and the residual water cavity comprises a residual water outlet and a residual water inlet communicating with the drainage cavity; and the negative pressure device communicates with the residual water outlet and is suitable for applying negative pressure to the residual water cavity after the drainage cavity drains water. The water cup assembly cannot be blocked, and the residual water removal effect is good. 本发明涉及家用电器技术领域，具体涉及一种水杯组件、排水系统及洗碗机，所述水杯组件包括水杯、余水排出结构和负压装置，所述水杯内部设有排水腔；余水排出结构内部设有余水腔，所述余水腔包括余水出口，及与所述排水腔连通的余水进口；负压装置与所述余水出口连通，并适于在所述排水腔排水后施加给所述余水腔负压。水杯组件不会堵塞，余水去除效果好。