The invention discloses a method for freezing and drying shellfishes. The method comprises the following steps: (1) cleaning the shellfishes by clean water; (2) removing shells and internal organs of the shellfishes, dicing and draining shellfish meats to obtain shellfish meat slices; (3) carrying out heating and sterilization treatment on the shellfish meat slices; (4) putting the shellfish meat slices in the step (3) into an anti-freezing agent water solution to infiltrate for 36-40 minutes, wherein the temperature of the anti-freezing agent water solution is 4-8 DEG C, and an anti-freezing agent is prepared from the following materials in parts by weight: 3-7 parts of lactitol, 4-10 parts of modified starch, 3-6 parts of glycerinum, 1-3 parts of potassium sorbate, 1-3 parts of chitosan, 2-5 parts of mussel lectin, 3-5 parts of sodium alginate, 6-10 parts of glucose and 1-3 parts of phytic acid; (5) putting the shellfishes treated by the anti-freezing agent into a quick-freezing warehouse with the temperature of 36-40 DEG C to carry out quick-freezing pretreatment, and then carrying out vacuum freezing and drying; and (6) putting into a moisture-proof package. The method disclosed by the invention has the advantages that the nutrition loss of the shellfishes can be effectively reduced and simultaneously the fresh taste of aquatic products is better protected.