肠衣，家畜的大、小肠经刮制而成的畜产品。主要用作填制香肠和灌肠的外衣；羊肠衣还可制成肠线，供制作网球拍线、弓弦和外科缝合线等用。肠衣按畜别分有猪肠衣、羊肠衣和牛肠衣。
Sausage coat is a livestock product made by scraping the large and small intestines of livestock. Mainly used for filling sausage and enema coat; sheep sausage can also be made into intestinal thread for tennis racket, bowstring and surgical suture. The casing is divided into pig casing, sheep casing and cattle casing.
按部位分有大肠衣、小肠衣。肠自内向外分成粘膜、粘膜下层、肌层和浆膜4层。根据畜别和加工成品的不同要求，对上面四层的处理也不一样。品质优良的肠衣应是坚韧半透明的。现在新兴的为胶原蛋白可食用肠衣。
There are large intestine coat and small intestine coat according to the location. The intestine is divided into four layers from inside to outside: mucosa, submucosa, muscular layer and serosa. According to the different requirements of livestock and processed products, the above four layers are treated differently. Good quality sausage should be tough and translucent. Collagen edible sausage is emerging.