Diarrhea diseases of piglets mainly include piglet paratyphoid, swine colibacillosis, swine clostridial enteritis, swine dysentery, swine infectious gastroenteritis, swine parasitic diseases, swine epidemic diarrhea and swine rotavirus infection. Preventive measures: ① Implement the "all-in and all-out" system, deworm pregnant sows before delivery, and do a good job in disinfection at all stages. (2) Strengthen pig feeding management, pay attention to piglet heat preservation and piglet feed preparation. (3) Live or inactivated vaccine of porcine transmissible gastroenteritis and epidemic diarrhea virus was used for vaccine immunization, and sows were immunized for 5 weeks 1 time and before delivery 1 week; Pregnant sows were immunized twice with trivalent inactivated vaccines of Escherichia coli K88, K99 and 987P 40 days before delivery and 15 days. The newborn piglets get passive immunity by eating colostrum, which can prevent yellow and white dysentery of piglets. The sows were immunized twice with inactivated Clostridium welchii vaccine 6-7 weeks and 3-4 weeks before delivery. Weaned piglets were immunized with live pig paratyphoid vaccine, and then immunized 1 time at the age of 50 days, which could prevent salmonellosis in piglets.