A method for cleaning a surface of a twin-roller continuous thin strip casting roller (10, 10'), each casting roller (10, 10') of the twin-roller continuous thin strip casting machine using two brush rollers (1, 1', 2, 2') arranged at the top and bottom for cleaning the surface thereof, wherein a rotational direction of at least one brush roller (1, 1', 2, 2') is the same as the casting roller (10, 10'), a linear speed of the casting roller (10, 10') is constant and greater than a rotational speed of the casting roller (10, 10'), and a roller surface cleaning device controls a distance or a pressure between the brush rollers and the casting roller (10, 10') by means of a position control device fixed on a casting roller (10, 10') bearing seat (30, 30'); at the beginning of casting, the brush roller (1, 1', 2, 2') is close to the surface of the casting roller (10, 10') and starts cleaning, as casting is processed, the roller surface cleaning device conducts relative displacement adjustment according to a expanding amount of the casting roller (10, 10') to keep a constant pressure between the brush roller (1, 1') and the casting roller (10, 10'); during the roller surface cleaning process, brush hair of the brush roller (1, 1') is pressed to be bent on the roller surface of the casting roller (10, 10') under an action of the position control device, the brush roller (1, 1') is shown to be partly flattened in macrocosm, a minimum flattening amount of the brush roller (1, 1') is a difference between a brush roller diameter r and a minimum diameter r min after flattening, that is: the flattening amount Δr = r-r min, unit: mm, the flattening amount is among 1-10 times of an average pit depth of a brushed roller (1, 1') surface of the casting roller (10, 10'), that is: Δr≤ • R c, and the average pit depth of the roller surface is measured by an average linear height R c of a roller surface contour unit; (the definition of R c is achieved from 〈〈Handbook of Mechanical Design〉〉, Mechanical Industry Press, 2000,P23-307); before casting operation starts, the upper and lower brush rollers (1, 1') get close to the roller surface simultaneously and rotate, a rotating speed of the lower roller is 0.2-0.5 time of that of the upper roller, a rotating speed of the upper roller is 1.5-3 times of that of the casting roller (10, 10'), and a pressure applied on the roller surface by the lower roller is 1-2 times larger than that of the upper roller; during a stable casting phase, the lower brush roller (1, 1') separates from the casting roller (10, 10') surface and keeps an interval of 0.1-1mm, therebetween; the rotating speed of the upper roller is 1.5-3 times of that of the casting roller (10, 10'); when the casting operation is to be over, a delivery system stops supplying molten steel, the lower brush roller (1, 1') gets close to the roller surface and rotates, while the rotating speed of the lower roller is 0.2-0.5 time of that of the upper roller, the rotating speed of the upper roller is 1.5-3 times of that of the casting roller (10, 10'), and the pressure applied on the roller surface by the lower roller is 1-2 times of the pressure applied on the roller surface by the upper roller; a unit pressure applied on the casting roller (10, 10') by the upper roller is 0.1-2.5MPa.