The invention provides a triple-stroke air-preheating radiant tube burner heat exchanger for raising the air-preheating temperature, lowering the exhaust gas temperature, improving the temperature efficiency and thermal efficiency of a heat exchanger. The triple-stroke air-preheating radiant tube burner heat exchanger comprises an end part choke plug, an inner fin tube, a multi-hole jet flow tube, a baffle ring, a middle duct, an air jet tube, a middle heat exchange duct, an exhaust gas stream guidance apparatus, a special-shaped flange, an external air duct, an expansion joint, a central fin heat exchange tube, an external heat exchange tube, an exhaust gas outlet tube and an air inlet tube, wherein the heat exchanger is divided into a build-in heat exchange region and an external heat exchange region by the special-shaped flange and the expansion joint. According to the triple-stroke air-preheating radiant tube burner heat exchanger, the air preheating temperature is improved, the exhaust gas temperature is lowered, and the temperature efficiency and thermal efficiency of the heat exchanger are improved.