The invention relates to a waste heat boiler system, a rotary hearth furnace high-temperature dust-laden smoke treatment system which is provided with the waste heat boiler system and a method for rotary hearth furnace smoke treatment applying the rotary hearth furnace high-temperature dust-laden smoke treatment system. According to the invention, an external smoke inlet is arranged on a sedimentation furnace of the waste heat boiler system, so that external high-temperature smoke is introduced in for diluting to-be-treated smoke; the dust concentration and harmful content concentration in the smoke are lowered; dust is prevented from being accumulated on the sedimentation furnace, a high-temperature heat exchange part and a low-temperature heat exchange part; the probability that smoke treatment equipment and a flue are blocked is lowered; meanwhile, corrosion of the smoke to the sedimentation furnace, the high-temperature heat exchange part, the low-temperature heat exchange part, the flue and the like is alleviated; stable operation of the waste heat boiler system and the rotary hearth furnace high-temperature dust-laden smoke treatment system is ensured; and the service life of the equipment is prolonged. Meanwhile, qualities of the smoke such as temperature can be ensured by the external high-temperature smoke, and the smoke waste heat utilization efficiency is ensured.