The invention relates to a floating type surface cleaning roller for a metal belt material, a strip steel rolling system adopting the floating type surface cleaning roller for the metal belt materialand a usage method of the floating type surface cleaning roller for the metal belt material. The cleaning roller comprises a roller seat and a flexible floating roller, wherein the roller seat is connected with a driving mechanism used for driving the roller seat to approach or be far away from a metal-belt-material running passage; the bottom of the roller seat is provided with a floating groove;the width of a groove opening of the floating groove is less than the diameter of the floating roller; the floating roller can be held in the floating groove and further the bottom end of the floating roller is located outside the floating groove, so as to be in contact with the surface of the metal belt material; a gas charging cavity is enclosed and formed by the floating roller and the groovewall of the floating groove; the roller seat is provided with a gas charging passage communicated with the gas charging cavity. The pressure of a gas in the gas charging cavity can uniformly act on the total length of the floating roller; the pressure and tension distribution in the width direction of the metal belt material is not influenced; when the surface of the metal belt material is uneven,the floating roller can generate different extrusion deformation along the axial direction of the floating roller; a cleaning blind area can be effectively overcome and the metal belt material is better cleaned.