Abstract: Existing cleaning devices for pressure filters face issues such as downtime cleaning affecting production continuity, periodic cleaning increasing cleaning difficulty, and low efficiency of water resource recycling. To address these problems, a negative pressure cleaning system for filter cloth, consisting of a cleaner, a wash-water separation chamber, and a wash-water circulation device, is proposed. This system utilizes the principle of negative pressure drive to achieve reverse dynamic cleaning of the filter cloth. By leveraging the solid-liquid separation function of the wash-water separation chamber and the secondary filtration of the circulation device, a closed-loop circuit of “cleaning—separation—filtration—reuse” is constructed. The results show that the system achieves simultaneous operation of filtration and cloth cleaning, which significantly improves the continuous operation time and filtration efficiency of the pressure filter. It removes residual coal slime on the cloth surface in real time, extending the service life of the filter cloth. Furthermore, it reduces the water cost of the coal preparation plant, with fresh water consumption expected to decrease by more than 30%. The negative pressure cleaning system for pressure filter cloth breaks through the limitations of traditional cleaning, achieves real-time cleaning and closed-loop recycling of wash water, effectively solves the key pain points of traditional cleaning technology, and meets the green and low-carbon development requirements of the coal preparation industry.