Medium element water soluble fertilizer is a kind of environment-friendly fertilizer without any hormone and residue. After being applied to the soil, it can make the roots of crops developed, the straw strong and the leaf color dark green, and improve the utilization rate of nitrogen, phosphorus and potassium in the soil. It can provide sufficient calcium and magnesium for the soil, improve the physical and chemical properties of the soil and protect the soil; When used in combination with a large number of element fertilizers, medium element water soluble fertilizer can make up for the physiological diseases caused by the lack of elements and make the crops absorb more comprehensive nutrition.