The utility model belongs to the technical field of mining belt conveyors and particularly relates to a passive belt sweeping water and coal separator. The problems that coal slime on a conveyor belt can not be cleaned easily, and due to the fact that conveyed materials contain a large amount of water, a bin is broken or the water in products exceeds the standard are solved. The water and coal separator comprises a first split bouncing flexible sweeper, a high-pressure water spraying hairbrush sweeper, a second split bouncing flexible sweeper and a water and coal separating device, wherein a support and an axis of the first split bouncing flexible sweeper are parallel to an axis of a head roller of a belt conveyor, and the water and coal separating device is arranged below the two split bouncing flexible sweepers and the hairbrush sweeper. The two split bouncing flexible sweepers are fixedly connected to the support. The hairbrush sweeper is fixed on the support, and the hairbrush sweeper and the head roller form a rotating pair rotating reversely. According to the water and coal separator, under the circumstance of not needing additional power sources, the two split bouncing flexible sweepers are utilized and combined with the hairbrush sweeper for sweeping the coal slime on the conveyor belt, and the water and coal separating device is utilized for separating the water and coal for the materials.