The invention provides an efficient string-type heating surface rapping dust-cleaning device which is mainly composed of string heating surface tube stack which is arranged in a furnace and a rapping mechanism which is arranged outside a furnace body, wherein the heating surface tube stack mainly comprises an L-shaped heating surface composed of a plurality of heat exchange tubes, one end of the L-shaped heating surface is fixedly connected with an upper header which plays roles in connection and suspension, the side end of the other end of the L-shaped heating surface is fixedly connected with an lower header which plays roles in connection and vibration transmission, a rapping base plate is welded on the outside of the lower header; the rapping mechanism which can carry out vibration rapping on the rapping base plate is arranged outside the walls of the furnace body corresponding to the rapping base plate; the rapping mechanism comprises a water-cooling rapping rod, a rapping hammer and a heat-insulation sound-insulation sealing cover; and the head of the water-cooling rapping rod extends into the furnace and is connected with the string heating surface tube stack, the rapping hammer with adjustable weight is used for rapping the water-cooling rapping rod, and the heat-insulation sound-insulation sealing cover is used for covering the rapping components. The device has characteristics of simple structure, reasonable design, low investment and operation cost, better dust-cleaning effect, low overhaul and maintenance rate, long service life, capability of effective cleaning special smoke in the medical solid waste incineration flue gas, and the like.