There are many problems associated with the aftermath of flooding caused by heavy rainfall. In addition to food spoilage caused by moisture, along with the flood water comes a variety of germs and germ-carrying bodies, which can easily lead to contaminated drinking water and cause various infectious diseases. So how can we accurately identify and prevent these infectious diseases? Bacterial dysentery: chills, high fever, abdominal pain, diarrhea, mucopurulent stools, etc. Typhoid and paratyphoid fever: high fever, toxic symptoms, splenomegaly, rose rash, etc. Hand, foot and mouth disease: mouth pain, anorexia, low fever, small herpes or small ulcers on hands, feet, mouth, etc. Preventive measures pay attention to dietary hygiene. Do not drink raw water, do not eat spoiled food, do not use sewage to wash fruits and vegetables, dishes, food soaked in sewage must be washed and eaten, raw and cooked food should be separated, food should be cooked and eaten. Avoid “disease from the mouth”. Wash hands before and after meals, dispose of garbage and feces in a timely manner, and strictly disinfect patients’ clothes and vomit. Protect water sources well. Disinfect drinking water with bleaching powder or bleaching powder tablets to ensure drinking of qualified water. Zoonotic disease Leptospirosis: high fever, headache, generalized aches and pains, calf pain, conjunctival congestion, swollen lymph nodes, etc. Preventive measures inside and outside the flooded houses, the first time to carry out disinfection work, it is recommended to use 84 disinfectant, according to the ratio of 1:60 with water and then spray the premises with a sprayer. Strengthen the management of domestic animals after the disaster to avoid animal excrement from polluting the surrounding environment with the flood. Insect-borne infectious disease epidemic hemorrhagic fever: fever, hemorrhage, congestion, hypotensive shock, kidney damage, etc. Schistosomiasis: fever, allergy, loss of appetite, abdominal discomfort, etc. Dengue fever: high fever, headache, muscle pain, skin rash, etc. Preventive measures against flies and mosquitoes. Try to prevent mosquito bites by wearing long sleeves and long pants, installing screens, using mosquito nets and other means. Skin inflammation eczema dermatitis: erythematous papules, itching, blisters, and even swelling, bacterial infection, etc. Preventive measures to avoid sharing sanitary ware, have to share sanitary ware, should let the healthy people first, the patient after the use, after using, and then the soap washed. If the skin and mucous membranes are contaminated by unknown blood, urine, oral secretions and excretions, they should be disinfected immediately. Reviewer: Li Lizhuo Li, Chief Physician, Department of Emergency Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China Chief Physician, Department of Emergency Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China