The invention relates to an aquatic collagen fish ball and a preparation method thereof. The fish ball contains the following raw materials by mass: 40-70% of aquatic collagen, 1-10% of soybean protein isolate, 5-15% of fat pork, 10-30% of starch, 0.5-2% of egg white protein, 0.5-5% of a thickening agent, 5-10% of a seasoning, 0.01-0.5% of a calcium salt, 0.1-1% of a protein cross-linking agent, and the balance ice water. The preparation method of the fish ball includes: preparing the aquatic collagen into gel peptone, conducting chopping, then mixing the chopped gel peptone with the soybean protein isolate in certain proportion, carrying out pulping and emulsification, then adding auxiliary materials, the protein cross-linking agent and the seasoning, mixing the materials evenly, then performing molding, quick-freezing, storage and packaging, thus obtaining the finished fish ball product. The fish ball provided by the invention has the characteristics of good heat resistance, delicious taste, good elasticity, crisp and tender taste, rich nutrition, and convenience eating. The preparation method of the fish ball provided by the invention has the advantages of simple operation, high efficiency and low cost, effectively solves the problems of poor heat resistance and lack of raw materials in traditional collagen products, and is suitable for popularization and application.