The invention discloses a liquid molten slag granulating and waste heat recycling device. The liquid molten slag granulating and waste heat recycling device comprises a granulating bin and a moving bed; the top center of the granulating bin is provided with a slag falling pipe; a granulator is arranged under the slag falling pipe; a plurality of cooling wall pipes are uniformly arranged on the inner wall of the granulating bin, and the lower portion of the granulating bin is provided with a granulating bin inlet header communicating with the plurality of cooling wall pipes; on the lower portion of the granulating bin, a granulating area buried pipe is arranged in a granulated slag granule free falling area; the moving bed is directly connected below the granulating bin; the upper portion of the moving bed is provided with a moving bed outlet header; a pulling thinning pipeline heating surface is arranged between the moving bed outlet header and the granulating bin inlet header; a dilute phase area buried pipe is arranged on the upper portion of the moving bed, and a scraper blade is arranged on the lower portion of the dilute phase area buried pipe; an air distribution device is arranged on the lower portion of the scraper blade; and a dense phase area buried pipe is arranged in a space between the air distributing device and the scraper blade. The liquid molten slag granulating and waste heat recycling device can effectively perform dry type centrifugal granulating on high-temperature molten slag, potential heat contained in slag granules is recycled efficiently, and it isguaranteed that the granulating bin and the moving bed can stably run.