Thio-sulfur combustion furnace, used in sulfur units of oil refineries. The furnace consists of an outer shell and a furnace lining, with the lining sequentially including an insulating layer, a heat-resistant layer, and a fire-facing layer. The insulating and heat-resistant layers form a castable material layer, containing anchoring pins, while the fire-facing layer is constructed from refractory bricks. This novel structure is rational, with a good overall lining integrity, high strength, excellent high-temperature and corrosion resistance, significantly improving the quality of the thio-sulfur combustion furnace and greatly extending its service life.