Purpose To observe the safety and efficacy of liquid infiltration method to separate lenticule in small incision lenticule extraction (SMILE).Method prospective study.72 patients were included in the study.Randomly selected one eye was performed conventional method; the contralateral eye was performed liquid infiltration method.Observed the Corneal Epithelium injury around the incision in surgery and the Smoothness of the lenticule edge under optical microscope.Compared the visual acuity, refraction, contrast sensitivity postoperatively though independent samples T test.