Abstract: In order to improve the mechanical and thermodynamic properties of the submerged arc furnace structure, in order to solve the problem of low efficiency caused by the concentration of thermal stress and uneven flow of the submerged arc furnace flue structure, a three-dimensional model of the submerged arc furnace including the furnace body, electrode, furnace lining and flue is established, and the thermal-stress multiphysics coupling simulation is carried out by ANSYS software, and the scaling is studied in combination with the model test. The simulation and test results show that the temperature attenuation of the flue of the submerged arc furnace before optimization is obvious, and there is a stress concentration in the furnace lining. After structural optimization, the temperature at the end of the flue is increased by 14%, the temperature distribution is more uniform, the stress and strain condition of the furnace body is improved, and the waste heat recovery efficiency is significantly improved. The research results provide a scientific basis for the optimization of submerged arc furnace structure, energy saving and consumption reduction and safe operation.