The two types of surgery are completely different: full femtosecond and semi-femtosecond, which are different in terms of surgical principles, surgical features, and applicable population. Through the corneal side incision, the lens is removed to correct myopia. Semi-femtosecond surgery is performed by a femtosecond laser to create the corneal flap first, and then the excimer laser to cut the corneal tissue and change the corneal curvature to achieve the purpose of myopia correction; 2. Different surgical features: the biggest feature of full femtosecond laser surgery is that there is no need to create a corneal flap, avoiding the dislocation of the corneal flap due to external forces, suitable for military personnel or athletes. It is also suitable for military personnel or athletes. The damage to the corneal nerve is less and thus the probability of dry eye is lower after surgery. In addition, there are fewer biomechanical changes in full femtosecond surgery compared to semifemtosecond surgery, so full femtosecond surgery is safer than semifemtosecond surgery, with a lower recurrence rate and a relatively faster recovery time after surgery. The most important feature of hemifemtosecond is that it can be precisely corrected according to the patient’s degree and the axis of astigmatism. The probability of infection in semi-femtosecond surgery is greater than in full femtosecond, but full femtosecond surgery is operated within the stromal layer, once the infection treatment difficulty increases; 3, the applicable population is different: full femtosecond surgery is mainly applicable to myopic patients with myopia below 800 degrees, semi-femtosecond surgery relative to full femtosecond laser surgery, the correction range is broader, generally for myopic patients below 1000 degrees. Full femtosecond surgery does not correct the higher order aberrations that affect night vision, while hemifemtosecond surgery does, and sometimes full femtosecond surgery can cause additional higher order aberrations. Patients who have higher order aberrations need to choose full femtosecond surgery with caution.