The invention relates to a fluorine-chlorine removal tower and a device and process for removing fluorine and chlorine from sulfuric acid by the fluorine-chlorine removal tower. The fluorine-chlorineremoval tower comprises a tower wall with an inner fluoroplastic layer and an outer steel base material layer, an air interlayer is arranged between the fluoroplastic layer and the outer steel base material layer, and a metal porous plate is arranged between the air interlayer and the fluoroplastic layer which is adhered to the metal porous plate. The fluorine-chlorine removal tower has advantagesthat the tower and the air interlayer are both vacuumized internally, and the vacuum degree of the air interlayer exceeds that of the tower; in the tower, sulfuric acid containing fluorine or chlorine contacts with low-pressure saturated steam to be heated and contacts with water to evaporate, so that fluorine or chlorine is separated from sulfuric acid and discharged from the tower along with steam to realize purification. By low-pressure saturated steam for direct heating and steam stripping, steam heat and sulfuric acid dilution heat are fully used, overhead steam temperature of a steam stripping tower is lowered under the vacuum condition, and low operating cost is realized; high fluorine-chlorine removal efficiency is realized, and conditions are created for recycling of sulfuric acid.