Professionally designed for high-salt, chlorine, fluorine, high-COD wastewater generated in the production process of pharmaceutical, pesticide, chemical, printing and dyeing industries. Traditional waste liquid incinerators often have low melting points of inorganic salts when treating the above wastewater. The high temperature in the furnace causes the inorganic salt to melt and build up the wall, which is difficult to ash, and even enters the subsequent sections with the flue gas, which affects the use of the equipment in the tail section, the exhaust fan has a high failure, and the equipment cannot run stably and continuously. The combustion device in this liquid adopts a positive pressure method. The inorganic salt melted at high temperature will flow down the furnace wall from top to bottom under the high pressure wind and be taken away by the cooling water in the quench tank. No inorganic salt will appear. Accumulation and wall formation, high acid removal efficiency, long device life and high continuous operation stability.