Fish scales are a unique natural biomaterial mainly composed of type I collagen. The highly ordered hierarchical microstructures and composition of fish scales are similar to human hard tissues, which give them good biocompatibility, degradability, and excellent mechanical properties. This makes fish scales suitable for potential applications in tissue engineering, biological filling, sewage processing, and flexible electronics. However, the practical application of fish scales is relatively limited due to a lack of commercial value, leading to serious problems such as material waste and environmental pollution. I developed an innovative process to extract liquid collagen from marine and freshwater fish scales, yielding around 25%. This process helps solve dumping issues, adds value, and manages pollution.