Used for the production of sulfide dyes, leather depilatory agents, metal smelting, photography, artificial silk denitrification, etc. Widely used in tanning, papermaking, ore dressing, dye production, organic intermediates, printing and dyeing, pharmaceuticals, monosodium glutamate, synthetic fibers, special engineering plastics, polystyrene sulfide, polyalkene rubber. It is also used in the production of sodium hydrosulfide, sodium polysulfide, sodium thiosulfate, etc., and has certain applications in the military industry.1. In the dye industry, it is used to produce sulfide dyes, which are raw materials for sulfide green and sulfide blue.2. In the printing and dyeing industry, it is used as an assistant dyeing agent for dissolving sulfide dyes.3. In the leather industry, it is used for hydrolysis to remove hair from raw hides, and it is also used to prepare sodium polysulfide to accelerate the soaking and softening of dry hides.4. In the papermaking industry, it is used as a cooking agent for paper.5. In the textile industry, it is used for denitrification of synthetic fibers and reduction of nitrates, as well as a mordant for dyeing cotton fabrics.6. In the pharmaceutical industry, it is used in the production of antipyretic drugs such as phenacetin.In addition, it is also used for the production of sodium thiosulfate, sodium hydrosulfide, sodium polysulfide, etc.