Preparation process of polypeptide for fertilizer

The invention is applicable to the field of preparation of fertilizer polypeptides, and provides a preparation process of a polypeptide for a fertilizer, the polypeptide for the fertilizer is produced by performing cleaning, impurity removal, crushing, degreasing, hydrolysis, enzyme deactivation, separation, concentration and drying processes on raw materials, the polypeptide is small in molecular weight and high in solubility, and no chemical or biological additive is added in the whole process. The polypeptide is guaranteed to be free of any heavy metal and chemical medicine residues from the source; the molecular weight of the polypeptide produced by the process is 500-1000 Daltons, and the polypeptide belongs to small-molecular oligopeptides, has specific biological activity, can enable normal expression of crop genes and enhance crop resistance so as to achieve the effects of increasing yield and improving quality, can be independently used, can also be added into fertilizers, and has good application pr