Water tank and cleaning machine

The invention relates to a water tank and a cleaning machine, the water tank comprises a water tank bottom plate, a water tank side plate and a surrounding plate, a first surrounding edge extending upwards is formed on the edge of the water tank bottom plate, the first surrounding edge is bent outwards to form a supporting table, the bottom of the water tank side plate is welded on the supporting table, a welding seam is reserved between the bottom of the water tank side plate and the supporting table, and the surrounding plate sleeves the periphery of the water tank side plate. The lower end of the coaming abuts against the supporting tables, the supporting tables are connected in a sealed mode, a cavity is defined by the inner surface of the coaming, the upper surfaces of the supporting tables and the outer surfaces of the water tank side plates, and the cavity is connected with an inner cavity of the water tank through welding seams. According to the invention, the water tank bottom plate and the water tan