Suffering from chronic hepatitis B, if platelets are low, not excepting splenomegaly and hypersplenism, may already have cirrhosis, and it is recommended to further test hepatitis B DNA and anti-hepatitis B virus treatment. Hepatitis B splenomegaly is mainly caused by portal hypertension, and the harms mainly include leukopenia and platelet lowering when hypersplenism is present, which makes it easy to have infections and bleeding. When splenomegaly is accompanied by hypersplenism, the patient’s peripheral blood picture shows leukopenia and thrombocytopenia, which can easily be complicated by infections and bleeding, such as recurrent peritonitis, ecchymosis of skin and mucous membranes, and severe intracranial hemorrhage, which are life-threatening. Patients are advised to follow the doctor’s instructions for further laboratory tests of hepatitis B DNA and anti-hepatitis B virus treatment, such as oral lamivudine or entecavir. Low platelets caused by hypersplenism can be treated by surgical removal of the spleen. In order to avoid the above situations, it is recommended that patients with hepatitis B should regularly review the two half pairs of tests, viral quantification, abdominal ultrasound, and timely antiviral treatment when there are antiviral indications, so as to slow down the progression of the disease.