Humic acid is the remains of animals and plants, mainly plant remains, formed through a series of processes of microbial decomposition and transformation, and geomorphization. It is a general term for a kind of natural organic substances that have common sources and behaviors. It is a complex mixture of macromolecular organic compounds rich in quinone groups, carboxyl groups, phenolic hydroxyl groups and other active functional groups and organic carbon. Studies have shown that the application of humic acid products has five major effects: improving soil, increasing fertilizer efficiency, stimulating crop growth, improving crop resistance and yield, and improving crop quality. Humic acid products will certainly play an important role in realizing high-yield, high-quality, and high-efficient modern agriculture.