<p>Waste cathode carbon block is a kind of hazardous waste generated during the overhaul of aluminum electrolysis cells. Waste cathode carbon blocks contain highly toxic fluoride and cyanide, and traditional treatment methods face problems of environmental pollution and resource waste. A high-temperature heat treatment furnace is an effective way to realize the separation of fluoride salts and carbon materials from waste cathode carbon blocks. In order to realize its efficient resource utilization, this study designed a new type of high-temperature heat treatment shaft furnace through numerical simulation and structural optimization, constructed a multi-physical field coupling model of electricity-heat-stress, and systematically analyzed the effects of the double-layer electrode layout (staggered versus parallel) on the uniformity of the temperature field and the effective heating zone in the furnace. The results show that the parallel electrodes combined with the rectangular furnace structure can significantly improve the calcination efficiency, the optimized outlet design supports the continuous graded production, and the overall refractory insulation of the new type of heat treatment furnace is further investigated with respect to the force and displacement under temperature loading. The study provides key process parameters for fluoride salt recovery and high-purity carbon material extraction. In turn, it achieves the purpose of improving production efficiency and resource utilization and provides solution ideas for the upgrading of hazardous waste treatment equipment.</p> Graphical Abstract <p></p>