1.Children whose conservative treatment is ineffective; 2.For older children with lacrimal duct obstruction (>5 months); 3.Children with a history of failed lacrimal duct exploration, children who have had one or more lacrimal duct explorations in other hospitals; 4.Children who are far away and need to travel to and from the hospital several times for treatment; 5.Parents who are willing to receive intubation once and are not willing to perform lacrimal duct exploration repeatedly; 6. Children with a family history of lacrimal stenosis; 7. Children younger than 5 months old, but with more obvious symptoms of neonatal dacryocystitis, or even with acute dacryocystitis. Because the nasal anatomy of older children is more complex, there are often multiple obstructions and adhesions in the lacrimal duct, common lacrimal duct, nasolacrimal duct, and in some cases, atresia of the lacrimal dots or even bony narrowing of the nasolacrimal duct. These cannot be solved by conventional lacrimal duct exploration surgery. There are also some children with a history of failed access, many of whom have tearing of the lacrimal duct and “pseudo-tracts”, so repeated access to the “pseudo-tracts” is very likely to cause serious tissue edema and secondary infection. Therefore, lacrimal duct reconstruction cannulation becomes the first choice for these children. Tear duct intubation should be considered.