One-step method of continuous producing sodium-alklis with mirability as raw material belongs to chem. engineering field. This invention adopts a heat accumulating pool-furnace with U-shaped flame; using gas as fuel, mirability as raw material, adequately adding accessory materials, through controlling right ingredient, reaction time and temp., treated by other process, the products of caustic soda, soda ash, vulcan alklis, sodium silicate have been continuously produced. The process is simple, operation is convenient, it can meet circumstances of market, corresponding to Chinese situation, and has good prospects.