The invention provides secondary cooling spraying equipment for high-drawing-speed production of a continuous casting machine for small square billets. The secondary cooling spraying equipment comprises multiple sections of spraying frames; each section of spraying frame comprises multiple spraying pipes; at one end, opposite to the drawing direction, of the secondary cooling spraying equipment, large air mist nozzles are arranged on the spraying pipes; front and back edges of adjacent spraying spots formed on continuously cast billets by the large air mist nozzles are overlapped completely; water sprayed on the surfaces of the continuously cast billets by every two adjacent large air mist nozzles is continuous; the height of the large air mist nozzles away from the continuously cast billets is gradually reduced in the drawing direction, so that complete overlapping of the front and back edges of the adjacent spraying spots in the drawing direction is changed into partial overlapping, and meanwhile, the covering area of the spraying spots in the cast billet width direction perpendicular to the drawing direction is gradually reduced. With the equipment, the cooling uniformity of the cast billets is improved by guaranteeing the uniformity of secondary cooling water spraying, so that the problems of off-square phenomena, internal cracks and the like after high-drawing-speed processing of small square billet variety steel are solved.