The falling film tube is the core equipment for caustic soda production, and the harsh process environment places high demands on the material and production processing of the equipment. Our company has been constantly exploring and summarizing our experience in the equipment, and has conducted sufficient research on the material of the equipment. We have also adjusted the distribution structure of the upper end alkaline solution based on the analysis of periodic damage on site, which has improved the film-forming effect after the alkaline solution flows in and avoided local dry burning caused by the deviation of the alkaline solution.