The invention relates to a preparation method of a low-value extraction recombinant minced hairtail product. The preparation method comprises the steps: mixing minced hairtail and a soybean protein isolate with a weight ratio of 1:4 in a chopper mixer, and extruding by adopting a homodromy twin-screw extruder, wherein the water content of a raw material is 30-50 percent, the rotating speed of screws is 80-120rpm, the temperature of the screws is 140-160 DEG C, and the optimal process condition is optimized by using a response surface method. Compared with that of a raw material, the in-vitro digestibility coefficient of the protein is increased by 10.25 percent. According to the preparation method, the low-value minced hairtail is recombined by adopting the homodromy twin-screw extruder, the advantages of high temperature, high pressure and high shearing force of an extrusion system are fully utilized, the degradation of macromolecules in a cylinder is promoted, the ordering transition of a protein array in the material is accelerated, the texturization and the specific retention of the material are improved; meanwhile, through passivating enzyme and damaging antinutritional factors, the in-vitro digestibility coefficient of the protein in the material is increased, and the nutritive value of the material is improved.