Introduction: NITI memory alloy for the medical field, in addition to the use of its shape memory effect or super elasticity, there are good biocompatibility. NITI can form a stable passivation film with the organism. In medicine, NITI alloy is mainly used in orthodontic treatment. In addition, the NITI shape memory alloy is used for various bone connectors, vascular clamps, coagulation filters and vasodilator components. At the same time, it also widely used in dentistry, orthopedics, cardiovascular, thoracic surgery, hepatobiliary, urology, gynecology, etc., with the development of shape memory, medical applications will be more extensive.