The invention discloses a heat exchanger for a raw coke oven gas ascending pipe. The heat exchanger for the raw coke oven gas ascending pipe comprises an upper flange, a lower flange and a cylindrical heat exchange assembly located between the upper flange and the lower flange, wherein the lower flange is provided with an annular flame shielding plate extending towards a heat exchange chamber of the cylindrical heat exchange assembly; the diameter of the smoke inlet of the flame shielding plate is greater than the diameter of the smoke outlet of the flame shielding plate; and the smoke outlet of the flame shielding plate is provided with a plurality of flow-disturbing vanes pointing to the center of the smoke outlet from the edge of the smoke outlet. According to the invention, through acceleration of the flame shielding plate and rotation of a guiding device, internal mixing of raw coke oven gas is reinforced, the convective heat-transfer coefficient of the raw gas and the inner wall surface of the heat exchanger is increased, and coking on the wall surface caused by high central temperature of the raw gas and low wall surface temperature is avoided. Damage of dry burning to the inner wall of the heat exchanger is avoided in a means of a built-in sleeve, and normal operation of a coking procedure is guaranteed during maintenance of a steam-water system.