Gelatins are natural polypeptide polymers obtained by partial hydrolysis of collagens. Due to their unique functional properties such as emulsifying, film-forming, foaming, gelling and excellent biocompatibility and biodegradability, gelatins have been widely explored and applied in food processing industry. Mammalian gelatins take up the main gelatin market share, but considering religious factors and health concerns, the application of mammalian gelatins in food processing industry has been restricted and questioned. Fish skin gelatins have similar functional properties to mammalian gelatins, and they can meet the requirements of people with special cultures and needs such as Islam due to the special sources, gradually becoming a key research object in food processing industry. In order to comprehensively introduce the application of fish skin gelatins in food, this paper summarizes in detail the use of fish skin gelatins as emulsifier, foaming agent, clarifier, thickener and gelling agent, as well as edible packaging, edible coating, emulsion and microcapsule, nanofiber and hydrogel preparation materials in food processing industry. Due to their unique functional properties, fish skin gelatins have shown better biological safety and processing characteristics than mammalian gelatins. Therefore, fish skin gelatins can be used as food additives, food packaging materials and active substance encapsulation materials in food processing industry. Thus, fish skin gelatins have good application prospects in food processing industry and are expected to become good substitutes for mammalian gelatins. This review paper can provide a basis for the future studies on improving the functional properties of fish skin gelatins and expanding their applications in food processing industry.