1. Used in the dye industry to produce sulphur dyes, which are raw materials for sulphur blue and sulfur blue. The printing and dyeing industry is used as a dyeing aid for dissolving sulphur dyes. In the tanning industry, it is used for hydrolysis to remove the hide skin, and it is also used to prepare sodium polysulfide to accelerate the drying of the skin by the dry skin. The paper industry is used as a cooking agent for paper. The textile industry is used for the denitrification of man-made fibers and the reduction of nitrates, as well as mordants for the dyeing of cotton fabrics. The pharmaceutical industry is used to produce antipyretics such as phenacetin. In addition, it is also used to prepare sodium thiosulfate, sodium hydrosulfide, sodium polysulfide and the like.

2. Adding an appropriate amount of sodium sulfide in the aluminum and alloy alkaline etching solution can significantly improve the surface quality of the etching, and can also be used for the removal of alkali-soluble heavy metal impurities such as zinc in the alkaline etching solution.

3. Sodium sulfide can also be used for the treatment of the conductive layer in direct electroplating, and the colloidal palladium sulfide is formed by reacting sodium sulfide with palladium to achieve the purpose of forming a good conductive layer on the non-metal surface.

4. Used as a corrosion inhibitor. It is also a raw material of sodium thiosulfate, sodium polysulfide, sulphur dye, and the like.

5, used in the manufacture of sulphur dyes, leather depilatory agents, metal smelting, photography, rayon denitration and so on.