Resource recycling is the key to achieving sustainable development, which allows us to protect the environment while also meeting the needs of economic growth. The by-products of animal bones are rich in collagen, oil, minerals, etc. However, a large number of animal bones have not been fully utilized. This article reviewed the collagen from the bones of 10 kinds of terrestrial animals, such as chicken, geese, sheep, and 5 kinds of aquatic animals, such as tilapia and tuna. Studies have shown that the bio-enzymatic hydrolysis method was most commonly used for the extraction of collagen from animal bones due to its high yield. Most of the bone collagen identified structurally is type I collagen. In addition, after isolation, it possesses a variety of biological activities, among which antioxidant activity is the most common and significant. This article could provide a theoretical basis for the further development of bone collagen extraction, structural identification, biological activity, and its application, which is of great significance for meeting the demand for high-value utilization of bone by-products.