A user drives a plugging piece to open a water outlet through a driving piece, a water inlet
buoy descends to a first preset height along with the height of the liquid level, water starts to flow out of a first water outlet and a second water outlet, water in the second water outlet flows through a foaming channel, and therefore foaming liquid and air are sequentially sucked into the
water flow to form foam; and meanwhile, the plugging piece descends along with the liquid level to close the water outlet, the first water outlet supplements water in the
water storage box until the water inlet
buoy ascends to the second preset height along with the liquid level, the foaming water
inlet valve is closed, and water discharging and foaming of the first water outlet and the second water outlet are stopped. Therefore, the device adopts a purely mechanical control foaming mode, a
peristaltic pump and a power supply module thereof are not used, the production cost and the use
noise are reduced, and the user experience is improved. Meanwhile, the foaming time can be changed by adjusting one or more of the flow of the first water outlet, the
drainage flow of the drainage port and the capacity of the
water storage box, and the diversified use requirements of users are met.