MMR usually refers to MMR vaccine, after the MMR vaccine high fever persistently does not go down should promptly consult the doctor, improve the relevant examination, and the doctor to give appropriate treatment. The MMR vaccine is an attenuated or inactivated virus or bacteria that can be used to prevent measles, mumps and rubella, three common acute respiratory infections in children. After receiving MMR vaccination, mild fever symptoms may occur, which usually resolve on their own after a period of time. However, if a high fever persists, it may not be a simple reaction to vaccination. If the fever persists after receiving MMR vaccine, first of all, appropriate antipyretic measures can be given, such as cold compresses, warm water baths and other physical methods to lower the temperature. And timely consultation, complete blood routine, blood culture and other related tests, to rule out whether the combination of other pathogenic infections, give acetaminophen and other antipyretic analgesic, and targeted treatment of primary diseases. Patients with persistent high fever after MMR vaccination should follow the doctor’s instructions for standardized treatment. At the same time, patients should pay attention to rest, drink more water, and strengthen the nutritional support, give high-calorie, high-protein, high-vitamin, easy-to-digest diet, and pay attention to the timely increase or decrease of clothing, in order to prevent upper respiratory tract infections, aggravate the disease.