With the advances in cataract phacoemulsification and intraocular lens implantation, more and more attention has been paid to the postoperative effects by both clinicians and patients. Meanwhile, the instruments for the preoperative measurements are also evolving. Various types of ocular biometers have emerged, which have evolved the principles from ultrasound to swept-source optical coherence tomography(SS-OCT). The OA-2000, a new type of SS-OCT based ocular biometer with fully automatic three-dimensional scanning, has the advantages of simple and safe operation, high resolution, excellent repeatability, fast measurement and good tissue penetration. It can obtain multiple ocular biological parameters in one measurement, which enables a wide application prospect. Here, we review the measurement principle and clinical application of OA-2000.