The present invention discloses a microwave-assisted processing method for controlling quality deterioration of a minced fillet product during a refrigerating process and belongs to the technical field of food processing. The method comprises steps of minced fillet manufacturing, mixing, molding, microwave post-processing, and refrigerating. By adding polylysine and using the microwave post-processing, the processing method controls the quality deterioration caused by the number of microorganisms during the refrigerating process of the minced fillet product. An addition concentration of the polylysine is 0.05%-0.2% and a microwave treatment intensity is 3W-7W/g, and the total number of the microorganisms is decreased and quality of gel strength, water holding capacity, etc. are improved during storage. The processing method can effectively control the number of the microorganisms in the refrigerating process of the minced fillet product, thereby controls the quality deterioration of the product and prolongs a shelf life of the minced fillet product.