旋转双棱镜系统通过两棱镜的共轴独立旋转改变光的传播方向，可用于调整光束或视轴指向。与传统的两轴、三轴式光电平台相比，基于旋转双棱镜设计的光束或视轴调整装置具有精度高、结构紧凑、动态性能好等优点，已成为传统光电平台的有益补充。本文分析了双棱镜系统的光束指向调整机制；介绍了国内外相关基础研究的热点问题，主要涉及光束转向机制、光束扫描模式、棱镜回转控制以及棱镜引起的光束变形、成像色差、成像畸变的研究。文中描述了该项技术的应用进展，给出了利用该项技术开发的典型产品以及该项技术在激光光束指向调整和目标搜索、识别与跟踪成像方面的应用。最后，探讨了旋转棱镜在扫描模式、光束质量、成像色差与畸变、回转控制等方面面临的技术难题，并对其发展趋势进行了展望。

The rotational-double-prism system can change the optical path by rotating separately the two prisms of a common axis, so that it can be used to steer the beams or the Line of Sight(LOS). Compared with the conventional two-axis or three-axis optical electro-optical gimbals, the rotational-double-prism-based beam or LOS steering devices offer tremendous advantages such as high accuracy, compactness and good dynamic performance, and have been proved to be the helpful complementarity for electro-optical gimbals. This paper analyzes the beam steering mechanism of the rotational-double-prism system, and introduces the key problems of the relevant theories for the beam steering, which focus on the beam deflection mechanism, beam scanning mode, prism rotation control, beam deformation, imaging aberration and the imaging distortion induced by a prism. It describes the research progress of engineering technology and gives several kinds of products based the rotational-double-prism system and their application to the laser beam steering and target searching, target recognition and traking imaging. Finally, the technical challenges concluded in scanning patterns, beam quality, chromatic aberration, image distortions and rotation control are discussed and the development trends are evaluated.