Abstract: Submerged combustion technology is a novel technology for natural gas pipeline heating. The core of the technology lies in the design of the heat exchanger. The design method of submerged combustion heat exchanger is introduced in this paper. The 200 kW submerged combustion heat exchanger is designed and put into use during the heating period of a gate station in Beijing. The measured data were used to calculate heat transfer coefficient of the convection inside and outside the tube, and the actual comprehensive heat transfer coefficient under rated design conditions was obtained through data fitting calculation, and then the comprehensive heat transfer coefficient of the design was modified. The calculation results showed that the modified comprehensive heat transfer coefficient of the design was 1.56. Through actual heat transfer coefficient of convection outside tube calculated by maximum velocity of water bath outside the tube, fitting for the relation between the power and the maximum velocity of water bath, using of heating equipment in the 120 kW and stable operation of the measured data validation, water bath maximum velocity calculation error rate is 6.67%. This method can provide a reference for the same type of submerged combustion heat exchanger design.