1, the whole knife surgery: Femtosecond laser combined with excimer laser is all-laser surgery, no longer use mechanical corneal lamellar knife. 2, the use of disposable package, greatly reducing the chance of cross-infection: each package has a series number, each series number can only be used for 1 person, greatly reducing the chance of cross-infection. Absolutely no repeated use like the lamellar blade. 3, femtosecond laser flap thickness precision: femtosecond laser cutting more accurate, precision is more than 100 times the traditional corneal knife, can cut a thinner flap, error is small, error control within 10-15 microns, postoperative safety is more secure; surgical source aberration reduction, postoperative visual quality is significantly higher than the lamellar knife excimer laser surgery, reduce the irregularity caused by uneven flap cutting Astigmatism, improve post-operative night vision and glare; faster recovery time and recovery effect of femtosecond laser. 4, femtosecond laser corneal flap cutting thickness almost at the same depth, less damage to the nerve: after surgery, eye dryness symptoms significantly reduced. 5, femtosecond laser flap, better neutralization (because the placement of the attractor ring can be fine-tuned again on the computer screen flap scanning position): less chance of damage to the corneal flap tip; parametric cutting creates good conditions, reducing the chance of off-center cutting, and thus reducing the surgical source of astigmatism. 6, postoperative corneal edge repair quickly, less postoperative foreign body sensation: femtosecond laser corneal flap, the edge of the corneal flap is cut vertically. 7, lower negative pressure, higher safety: the negative pressure of the suction ring used to create the corneal flap with the da Vinci femtosecond laser (about 35 mmHg) is significantly lower than the negative pressure of the mechanical corneal lamellar knife to create the corneal flap (about 65 mmHg), greatly improving surgical safety. 8, the chance of external forces leading to corneal flap displacement is reduced: femtosecond laser-made corneal flap, corneal flap repair is more solid than laminate knife. 9, less chance of epithelial implantation (because the flap does not require the blade to enter the corneal layer, so it will not bring the corneal epithelium into the corneal layer): epithelial implantation into the corneal layer is a more troublesome complication, seriously affecting vision. 10, broader indications: patients who cannot undergo traditional surgery because their myopia is too deep and their cornea is too thin can choose femtosecond laser surgery. 11. Safer: The intraoperative risk caused by the use of a keratome is eliminated, and the possibility of serious complications that threaten postoperative vision is greatly reduced.