The five viruses known to cause viral hepatitis are A, B, C, D and E. Hepatitis E virus (HEV) infection can lead to acute jaundice type hepatitis, and the majority of patients respond well to the disease for about 1 to 2 months. Older patients with hepatitis E tend to have bilious hepatitis with an extended recovery period. Only a very small number of patients develop heavy hepatitis and have a poor outcome. It should be noted that patients with chronic hepatitis B should pay special attention to the prevention of hepatitis E virus infection. Overlapping hepatitis E on top of hepatitis B virus (HBV) infection often leads to deterioration of liver function and development of severe hepatitis, resulting in acute or subacute liver failure, poor outcome and high mortality. According to domestic and foreign literature, the incidence of heavy hepatitis in chronic hepatitis B patients with overlapping HEV infection is 27-32%, while the incidence of heavy hepatitis with HBV infection alone is only 4-6.3%. We admit patients with severe hepatitis B and E overlap infection, due to serious liver damage, not only is it difficult to treat, but some of them also have various complications of heavy hepatitis, which increases the suffering of patients and also adds a heavy economic burden. Therefore, it is important for hepatitis B patients to actively prevent HEV infection. Patients with hepatitis B should be alert to combined hepatitis E infection when the following conditions occur: sudden appearance of acute hepatitis-like manifestations such as weakness, nausea and vomiting, low body temperature, deepening jaundice, etc. in the stable stage of liver function, biochemical index of liver function, glutathione transaminase (ALT) > 500 U/L, and serum bilirubin (TBil) significantly higher than normal. When there are above manifestations, hepatitis E antibody (anti-HEV) should be tested promptly, if anti-HEV (+) both suggest overlapping hepatitis E virus infection. At this time, hospitalization, bed rest, close observation of changes in the condition, detection of changes in the biochemical indicators of liver function, to prevent further deterioration of the condition. The transmission route of HEV is different from that of hepatitis B virus, mainly through the gastrointestinal tract, eating and drinking food and water contaminated by the virus can cause infection. Therefore, the main preventive measures are to pay attention to personal dietary hygiene, wash hands before meals, and avoid eating in restaurants with poor sanitary conditions and using unhygienic tableware. In China, there are many patients with chronic hepatitis B. Prevention and timely detection of overlapping infections of hepatitis E can help reduce the worsening activity of chronic hepatitis and morbidity and mortality, and prevention should be advocated to avoid the occurrence, early detection and timely treatment.