A mopping apparatus and a cleaning device for floor cleaning are disclosed. The cleaning device comprises the mopping apparatus and a sewage tank (710). The sewage tank (710) collects water and/or dirt of the mopping apparatus. The mopping apparatus comprises a roller brush (1), a threaded conveying rod (21), and a sewage holding groove (62). The threaded conveying rod (21) is arranged at one side of the roller brush (1). The threaded conveying rod (21) is arranged in proximity to or attached to the roller brush (1). The threaded conveying rod (21) is rotatably mounted in the sewage holding groove (62). The threaded conveying rod (21) is arranged in proximity to or attached to an inner wall of the sewage holding groove (62). A sewage holding groove opening (622) is provided at one side of the sewage holding groove (62) facing the roller brush (1). Sewage on a surface of the roller brush (1) is squeezed and removed by the threaded conveying rod. This favors product miniaturization or diversified designs, provides an excellent sewage removal effect, has an ingenious design and a simple structure, and is simple to operate and convenient to use. The modularized design facilitates the assembly and the disassembly of the parts for replacement or maintenance. Sewage is conveyed from one end of the threaded conveying rod (21) to the other end. The protruding and recessed surface of the threaded conveying rod (21) kneads, pats, and squeezes the roller brush (1). A roller brush assembly is mounted and demounted in one piece.