There are two ways to cut double eyelids, one is surgical incision and the other is catgut embedding. Surgical incision of double eyelids is to cut a small wound on the upper eyelid, so as to remove excess skin tissue and then suture the wound. Embedding thread to cut double eyelids is to bury special thread on the upper eyelid to achieve the effect of double eyelids. According to custom, canthus opening is generally divided into life canthus opening and surgery canthus opening. Life double eyelids achieve the effect of double eyelids by sticking special eyeliner for beauty on the upper eyelids, but this effect is short-lived and reversible. Open canthus surgery is the ultimate step of eye modification. After opening the corner of the eye, the eyes are more radiant and vivid. General experts will suggest that the two should be done together, and the combination of the two can achieve the effect of aesthetic complementarity.