Pediatric lacrimal duct obstruction is a common condition in infancy, mostly within the first month of life. The main manifestations are lacrimation or tears in the eyes and mucus overflow from the eyes. It can develop in one or both eyes. The main cause is postnatal obstruction of the lower nasolacrimal duct (the duct that drains tears). Some children may heal on their own by 3 to 6 months of age, and the tearing symptoms disappear. This self-healing will become less likely with increasing age and more likely with secondary infection, purulent discharge and conjunctivitis or even acute inflammation. Therefore, when the child is 3 to 6 months old and the tearing symptoms persist and there is often purulent discharge (purulent eye mucus), lacrimal drainage should be preferred, so that the lacrimal drainage is open and bacteria will not breed in the tear sac and cause inflammation. Tear duct lysis is a safe and reliable treatment for infants and children with tear duct obstruction or combined dacryocystitis, with a cure rate of more than 90%. Parents should follow the doctor’s advice and not delay treatment blindly.