The reason is generally believed to be related to heredity. The main reason is that the levator palpebrae superioris muscle, which is used to lift the upper eyelid muscle, is underdeveloped, or the motor nerve function that dominates this muscle is incomplete, so that the eyes cannot be widened, and the drooping eyelids cover some pupils. At present, the most ideal treatment for congenital ptosis is cosmetic surgery. At present, there are three effective surgical methods in China: L. Shortening levator palpebrae superioris muscle. This method is to shorten the levator palpebrae superioris muscle to achieve the purpose of lifting eyelids, which is suitable for children with mild ptosis. 2, frontalis fascia suspension method This method is to use a small piece of fascia lata of autologous thigh to connect with frontalis muscle and upper eyelid, and use frontalis muscle contraction to strengthen the strength of levator palpebrae superioris muscle, because the suspended fascia may become loose in the future, sometimes it will affect the surgical effect. This is also a method to strengthen the function of levator palpebrae superioris muscle by using the contraction of forehead muscle. Even if the eyelid muscles completely lose their function, better results can be obtained. The advantage of this operation is that only a small incision is made at the eyelid fold (double eyelid line), and the frontalis muscle flap can be separated and transferred to complete the operation, which plays a role in expanding eyes and has a reliable and lasting effect.