Abstract: Influencing factors on heat efficiency of tubular heaters are analyzed, which mainly include excess air factor, imperfect combustion and exhaust temperature. Measures to increases heat efficiency of tubular heater are presented, including raising the temperature of air that goes into firebox, control excess air factor, decreasing imperfect combustion loss/heating loss and cutting down exhaust temperature, in which cutting down exhaust temperature is considered as a most effective method. As decrease of exhaust temperature is easier to result in dew point corrosion, it is described in detail and a solution to solve the problem is presented.