The box is smooth and free of scale, easy to clean, and not prone to residual water stains and scale. The sewage tank is free from scale and does not stick to water. It can be cleaned immediately with clean water, and is not prone to residual water stains or scale. It remains clean even after long-term use. Durable and resistant to aging, not easily deformed, and does not leak after long-term use. Replace the clean water tank, store a clean water source, and provide stable water supply for mopping and mopping. Continuous water supply for cleaning the mop improves cleaning efficiency, the box structure is sealed to prevent dust from falling in, and the water source is kept clean for a long time.