Ferrous sulfate can be used as fertilizer additive to supplement the necessary trace element iron for plants, and promote their absorption of nitrogen, phosphorus and other elements. Applying ferrous sulfate (particles) as base fertilizer to soil could prevent yellow leaf disease of flowers. When combined as a leaf fertilizer, the solution can also prevent many pests or diseases, such as rice fever, chlorosis, cotton anthracnose, and so on. Adding ferrous sulfate to feed can effectively prevent and treat hypochrome microcell anemia caused by widespread iron deficiency, prevent and treat iron deficiency mental depression, shoulder bone edema, dyspnea, impaired body function, uncontrolled temperature regulation, abnormal body temperature and other diseases, and improve feed reward. In addition, ferrous sulfate can also be used in water treatment, making iron salts, mordant, preservatives and other fields.