Cost-effective method for extracting fish scale collagen having large molecular weight

A cost-effective method for extracting fish scale collagen having a large molecular weight, comprising:

• 1) performing pretreatment, comprising:
• collecting and packaging fish scales, followed by repeated frozen storage and thawing to obtain pretreated fish scales;
• 2) performing impurity protein removal, comprising:
• removing fish silver from the pretreated fish scales obtained in the step 1) and cleaning with pure water;
• and soaking the cleaned fish scales in a salt solution to remove impurity proteins, rinsing the fish scales with purified water until clear, followed by drying;
• 3) performing fish scale collagen extraction, comprising:
• mixing the dried fish scales obtained in the step 2) with purified water according to a ratio of 1:5 to 1:20, subjecting the mixture to hydrothermal extraction at 40° C. to 100° C. for 1 to 4 hours, performing solid-liquid separation, and collecting the solution as a fish scale collagen extract;
• and
• 4) pre-cooling and lyophilizing the fish scale collagen extract collected in the step 3) to obtain a solid fish scale collagen product.