The enzymatic hydrolysis experiments on the water extract of Spanish mackerel byproducts were conducted. Through single factor and orthogonal enzymolysis experiments, the enzymatic hydrolysis process of mackerel byproducts was optimized, and the enzymatic hydrolysate was used to process seafood sauce. The sensory quality between the commercial and the homemade seafood sauces were compared and analyzed. The results show that the best enzymatic hydrolysis technology for Spanish mackerel byproducts were gained as follow: the amount of neutral protease of 500 U/g, the ratio of liquid to material of 3∶1, the enzymatic hydrolysis temperature of 55 ℃, the pH of 7.5, and the enzymolysis time of 5 h, the amino acid nitrogen of the enzymolysis solution produced under the enzymolysis conditions was as high as （0.325±0.004） g/100 mL. The homemade seafood sauce had reached the taste of commercial seafood sauce. The physicochemical and microbiological indicators of the seafood sauce products met the requirements of relevant national standards.