Cataract is one of the common eye diseases that endanger human health and is the primary cause of blindness in the elderly. Cataract surgery has developed rapidly in the past half century, and has gone through three stages: intracapsular cataract extraction, extracapsular cataract extraction and ultrasound emulsion extraction, and the surgical incision has also changed from 11mm in the capsule, to 7mm in the extracapsular, to 3mm in ultrasound emulsion, with the trend of smaller and smaller incisions. At present, most of the cataract ultrasonic emulsification surgeries performed in China have an incision of 3.0-3.2 mm. The size of the surgical incision is related to postoperative astigmatism, inflammation, and the speed of postoperative recovery. Alcon USA’s ultrasound emulsification system is the most advanced cataract ultrasound emulsification device in the world. Its unique twisting mode provides microincision-coaxial cataract surgery technology. Its newly developed surgical system can further reduce the cataract surgical incision from 3.2mm to 2.2mm, which reduces surgical trauma and complications, and greatly improves the safety of surgery. Cataract patients can quickly recover their vision after surgery, and the astigmatism caused by the surgical incision has been significantly reduced. Clinical research data reported that a 3.0mm surgery can produce 0.33D astigmatism, while a 2.2mm surgery only produces 0.11D astigmatism, and such a small amount of astigmatism has negligible effect on postoperative vision. Therefore, the microincision-coaxial cataract ultrasound emulsification technique not only shortens the recovery time of patients, but also significantly improves the postoperative vision of cataract patients.