A one year old child with a knocked out tooth can be compressed to stop the bleeding first, and pay attention to observation. A one-year-old child’s teeth knocked out should first check the wound for tooth fragments and other things that need to be removed in time. Also need to carry out symptomatic hemostasis, can use sterile gauze for compression to stop bleeding. In addition, children should be careful not to brush their teeth on the same day, and parents should be careful not to let the baby lick the wound. The baby should also be observed to see if there is a large amount of fresh blood coming out, and if there is, the baby should seek medical attention promptly. Since children over one year old have milk teeth and the milk teeth have not fully erupted, they cannot wear retainers for the time being. At the age of 6 to 11 years old, there will be the eruption of permanent teeth, if the gap is too small, it may affect the subsequent eruption of permanent teeth, resulting in the occurrence of pericoronitis. Therefore, parents need to pay attention to the eruption of the baby’s teeth, if the baby can cooperate with the treatment, you can wear a gap retainer to ensure that the distance between the two teeth, so that the subsequent permanent teeth have enough space to erupt. A one-year-old child with a knocked-out tooth should be treated promptly and seek medical attention if necessary to avoid delay.