Sodium sulfide is mainly used as raw material for raw leather unhairing agent, pulp cooking agent, sulfide dye, dye intermediate reducing agent, fabric dyeing mordant and ore flotation agent, as well as viscose fiber desulfurizer and raw material for production of sodium hydrosulfide and sodium polysulfide. In the dyestuff industry, sodium sulfide is used to produce sulfur dyes, which is the raw material of sulfur blue and sulfur blue. In the printing and dyeing industry, sodium sulfide is used as a dyeing aid to dissolve sulfide dyes. In the leather industry, sodium sulfide is used to hydrolyze the raw hide to remove hair, and to prepare sodium polysulfide to speed up the soaking of dry skin to help soften. In the paper industry, sodium sulfide is used as a cooking agent for paper. In the textile industry, sodium sulfide is used for denitrification of man-made fibers, reduction of nitrocellulose and mordant for cotton dyeing. In the pharmaceutical industry, sodium sulfide is used to produce pyrolytic drugs such as phenacetin. In addition, sodium sulfide is also used to prepare sodium thiosulfate, sodium hydrosulfide, sodium polysulfide, etc.