Eight or nine-year-old child knocked on the head of a large bag is recommended to carry out local cold compresses, avoid rubbing, if the child appears to be mentally unstable, vomiting, drowsiness need to consult a doctor in a timely manner. 1. Local cold compresses: within 72 hours of the injury, you can apply local cold compresses to the child’s bump, which can shrink blood vessels, reduce oedema oozing, and also reduce pain. 2. Avoid rubbing: Avoid rubbing the area for the first time, which may aggravate the damage of the surrounding tissues, and apply hot compresses after 72 hours to help blood circulation and absorption of the lumps. 3. Timely medical treatment: Parents need to closely observe the child’s reaction, if there is mental instability, vomiting, drowsiness, slurred speech, etc., as well as parents can not deal with the situation, it is recommended to seek medical treatment in a timely manner, improve the brain CT and other tests to detect intracranial hemorrhage.