The utility model provides a tubular coal tar heating furnace, includes furnace body, heat -exchanger furnace pipe, combustor, heat radiation enhancement device, the furnace body includes the radiation chamber and sets up the convection chamber in the radiation chamber top, radiation chamber, convection chamber pass through the intercommunicating pore intercommunication, the heat radiation is strengthened the device setting and is in in the radiation chamber, and be close to convection chamber, the heat radiation is strengthened the device and is the conical body, and the summit sensing of device is strengthened in the heat radiation the bottom of radiation chamber, the bottom surface that the device is strengthened in the heat radiation is close to convection chamber, the device is strengthened in the heat radiation bottom surface with form the clearance between the lateral wall of radiation chamber, the heat radiation is strengthened the device and is blockked the produced high -temperature gas of coal gas burning to the guide high -temperature gas flow direction sets up the heat -exchanger furnace pipe back of radiation chamber gets into from the clearance again convection chamber to high -temperature gas is in through the extension detention time in the radiation chamber comes to give the intraductal coal tar of heat -exchanger furnace with the abundant transmission of high -temperature gas's heat.