The box is smooth and free of scale, easy to clean, and not prone to residual water stains and scale. The water level mark is clear, and adding water is more accurate to avoid excessive overflow. The remaining water level can be checked in real time to avoid interruption of cleaning due to water shortage. 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.