At present, most hydrogels used in the food industry are natural polymers, with poor mechanical properties and high moisture content, which is easy to be contaminated by microorganisms, making it difficult to meet the use needs. In recent years, new composite hydrogels loaded with active substances prepared from natural and synthetic polymers or modified natural polymers have been increasingly used in the food field..Starting from the preparation method of composite hydrogels, this paper introduces its application status in food packaging materials, fat and starch substitution, bioactive molecule delivery, rapid detection of microorganisms, and prospects the development trend of composite hydrogels in the food industry.