The optical phased array technology has the advantages of fast response speed, compact structure, and flexibility in control, thus it has been widely used in many scientific and technological fields. Over the past 50 years, many excellent research results have emerged. To give an overview of the optical phased arrays, the article first briefly reviews the history of the optical phased arrays, and introduces the basic principles. From the perspective of different applications including beam projecting and receiving, combined with the author’s thinking, the current status of the developments in high-quality laser source, laser coherent combining, laser steering, atmospheric distortion correction, and synthetic aperture imaging are introduced in detail. Finally, the bottleneck and the future development trends of the optical phased arrays are given.