Used as analytical reagent and oxidant, and also used in the synthesis of potassium salt and the preparation of explosives.

In the food industry, it can be used as a hair coloring agent, color protection agent, antimicrobial agent, and preservative. For example, it is used for curing meat and has a preservative effect in luncheon meat. It is the raw material for making black powder, such as mine powder, fuse, firecrackers, etc. Also used in fireworks to produce purple sparks. Mechanical heat treatment is used as a salt bath for quenching. The ceramic industry is used to make enamel paint. Used as a glass clarifier. Used in the manufacture of glass bulbs for automobile lamps, glass bulbs for optical glass kinescopes, etc. The pharmaceutical industry is used to produce penicillin potassium salt and rifampin. Used to make cigarette paper. Used as a catalyst. Dressing agent. Used as compound fertilizer for crops and flowers.

Potassium nitrate is also a hair color agent allowed in China. It is reduced to potassium nitrite due to the action of bacteria in meat products to protect color and inhibit bacteria. According to Chinese regulations, it can be used for meat products, the usage amount is 0.5g/kg, and the residual amount shall not exceed 0.03g/kg. Used in the manufacture of fireworks, matches, ceramic glazes, fertilizers, etc. Industrial potassium nitrate is also widely used in the manufacturing process of strengthened glass.