1. In the dye industry, it is used to produce sulfurized dye, which is the raw material of sulfurized blue and cyan. The dyeing and printing industry is used as a dye aid for dissolving sulfide dyes. In leather industry, it is used to hydrolyze and depilate raw hide, and to prepare sodium polysulfide to accelerate the soaking and softening of dry hide. The paper industry is used as a cooking agent for paper. Textile industry is used for denitrification of man-made fiber, reduction of nitrated fabric and mordant for cotton fabric dyeing. The pharmaceutical industry is used to produce phenacetin and other antipyretics. 

2. Adding appropriate amount of sodium sulfide to alkaline etching solution of aluminum and alloy can improve the surface quality of etching obviously, and can also be used to remove zinc and other alkali soluble heavy metal impurities in alkaline etching solution.

3. Sodium sulfide can also be used for the treatment of conductive layer in direct electroplating. Through the reaction of sodium sulfide and palladium to form colloidal palladium sulfide, a good conductive layer can be formed on the non-metallic surface. 

4. Used as corrosion inhibitor. It is also the raw material of sodium thiosulfate, sodium polysulfide, sulfur dyes, etc.

5. It is used to make sulfurized dyes, leather unhairing agents, metal smelting, photography, rayon denitration, etc.