Water tank and cleaning device

The utility model discloses a water tank and a cleaning device, the water tank comprises a tank body and a tank cover, the tank body is provided with a first opening and a first cavity, and the tank cover is detachably installed in the tank body and covers the first opening. The outer edge of the upper end of the box body side wall at least partially surrounds the outer edge of the upper end of the box cover side wall in the circumferential direction of the box cover side wall; wherein the side wall part of the box cover, which is not surrounded by the side wall of the box body, is a first area, and the side wall part of the box cover, which is surrounded by the side wall of the box body, is a second area. According to the water tank provided by the utility model, when the tank cover is arranged in the tank body, the outer edge of the upper end of the side wall of the tank cover is partially covered by the side wall of the tank body, so that the tank cover is nested in the tank body, and the tank body and the