Gelatin is a hydrophilic colloid, usually extracted from collagenous parts of connective tissues such as animal skin, bone and fascia. It can be divided into edible gelatin, medical gelatin, photographic gelatin and industrial gelatin according to its usage and quality index. For edible gelatin and medical gelatin, a small amount of consumption and contact will not cause harm to human body, while the latter two types of gelatin are prohibited to avoid harm to human body.1. Edible gelatin: usually widely used, gelatin exists in jelly, soft candy, meat products and other foods. And gelatin is a natural nutritional food thickener, contact with the human body will not be harmful, appropriate consumption does not make people fat, and will not lead to physical decline. But need to pay attention to the amount of intake, if excessive intake, may lead to indigestion and other symptoms, exposure to no harm; 2, medical gelatin: mainly used in the production of pharmaceutical products gelatin, help cod liver oil molding, can be made into capsules, as gelatin does not melt quickly in the mouth, esophagus, so that the drug ingredients can be smoothly sent to the intestines, to improve the efficiency of drug absorption. Exposure or intake of gelatin through medication is usually not harmful to humans; 3, photographic gelatin: mainly used in the production of light-sensitive materials, photographic gelatin is prohibited to eat, so as not to damage the gastrointestinal tract mucosa, endangering human health, occasional ordinary exposure to the body generally does not produce significant harm; 4, industrial gelatin: mainly made of waste leather boiling, which contains heavy metal chromium, human intake will damage the bones and hematopoietic Stem cells, excessive intake or long-term exposure may lead to osteoporosis, and even cancer, and the harm of heavy metal chromium on the human body is a slow process, which may affect the health of people by osmosis.