The main raw material of fish protein liquid fertilizer is fish by-products, such as fish bones, fish skin, fish scales and so on. Selection of suitable raw materials is an important guarantee for the manufacture of high-quality fish protein liquid fertilizer.

Crush and sieve the fish by-products to remove impurities and make the raw materials uniform and delicate.

Put the treated raw materials into the enzyme tank, add appropriate amount of water and protease to carry out enzymatic treatment. The time and temperature of enzyme digestion need to be adjusted according to specific conditions.

Filter and separate the liquid after enzyme digestion, remove the solid material and get fish protein liquid.

Concentrate the fish protein liquid to make it reach a certain content of dry matter, and then carry out spray drying or roller drying and other treatments to make fish protein liquid fertilizer.