Congenital cataracts have different clinical manifestations, and the degree of vision loss is related to the location and extent of lens clouding. At present, congenital cataract is still mainly treated by surgery, and mastering the appropriate timing of surgery is an important aspect to decide whether the child can recover his vision. In general, the following principles should be mastered: 1. For those who have complete cataract in both eyes after birth and whose visual function is seriously affected by the lack of normal stimulation of the retina, surgery should be performed as early as possible. Generally, surgery should be performed within 1-2 months after birth, and no later than 6 months. The other eye should be operated shortly after the surgery of the first eye, and the postoperative monocular masking should not exceed 1 week to prevent the occurrence of form deprivation amblyopia due to monocular masking after surgery. 2. Incomplete cataract in both eyes: according to the degree of vision loss and the location and extent of lens clouding, early surgery should also be pursued. 3. For congenital cataract in one eye, if the lens clouding is located in the pupil area, or if the visual acuity of both eyes is less than 0.3, surgery should be performed as early as possible. In conclusion, the importance of early surgery must be emphasized, and corrective glasses should be worn as early as possible after surgery to avoid amblyopia, and the second phase of IOL implantation should be performed later according to the patient’s eye development and visual acuity.