The invention discloses a protein powder product produced from fish dissolved pulp, and the protein powder product is prepared from the fish dissolved pulp by marine Brevibacterium oxydans secreting alkaline protease enzymolysis, papain enzymolysis, ultrafiltration and freeze-drying. The beneficial effects are as follows: the protein powder obtained by the method is rich in vitamins such as VB1, VB2 and Vc, and various minerals such as calcium, phosphorus, iron and the like, and has rich nutrition; the protein has small molecular weight, is easily absorbed by the human body, has excellent oxidation resistance, and can be used for preparing functional food. The fish dissolved pulp is used as a raw material, environment is protected, resources are reasonably used, and the added value of the fish dissolved pulp is increased.