Fever after hepatitis B vaccination is a common adverse reaction to vaccination, and treatment is mainly symptomatic. If the fever is above 39 ℃, you can take some antipyretic drugs, merlin or ibuprofen, or pediatric antipyretic suppositories can be, at the same time, let him drink more hot water, with warm water to rub him, also help to lower the temperature. If the fever is below 39 ℃, and the child’s mental state is also OK, this time there is no hurry to use antipyretic drugs, give him a patch with a cooling patch, drink more hot water can also help to cool down the temperature, the general vaccination-induced fever seldom lasts more than 48 hours. If the fever remains high for more than 48 hours, it is best to go to the hospital to check the blood count and C-reactive protein to see if there is any other reason.