Most of the pus in the gums of 3-year-old children can be eliminated by themselves in 2~3 days, pay attention to a light diet and keep the mouth clean. If the symptoms continue to worsen, you need to drain the abscess, or do root canal treatment. 3-year-old children with pus in the gums is mostly gum infection, if the symptoms are mild, most of the 2~3 days can be eliminated on their own, pay attention to light diet, keep the mouth clean, drink more water. If the abscess continues to increase in size, surrounded by redness and swelling, the need for stomatologists to incise the abscess drainage, drainage of pus, oral cephalosporin antibacterial drug treatment as prescribed by the doctor. If the diagnosis is chronic apical periodontitis, you need to drill the damaged tooth, clean the necrotic tissue inside the tooth, fill the tooth with specialized materials, and slowly change the medication until it gets better. 3-year-old children with long abscessed gums need to take their children to the hospital in time to find out the cause of the disease before treatment.