随着飞行器技术成熟与经济需求激增，低空飞行“有无人异构、高密度融合、自主化运行”等特点凸显，对低空空管提出了严峻挑战。数字低空通过在信息空间内数字化重构物理飞行空域，将面向对象的传统空域管理模式转化为面向空域的资源计算与优化问题，充分发挥空域空间不变性优势，降维大规模飞行对象的管控业务复杂度；在此基础上，发展一套空地一体的数字化交通态势感知与协同防撞技术，降低无人机空域进入带来的安全风险。本文首先梳理了低空空管需求与发展趋势，其次重点介绍数字低空空域计算理论的基本原理，再从不同层面论述了融合运行的技术难点问题，为安全高效的数字低空融合运行技术体系构建研提出可行技术路径。

With the development of aircraft technology and the surge of economic demand, the characteristics of low-altitude flight such as "manned-unmanned heterogeneous, high-density integration, autonomous operation" have become prominent, which poses a severe challenge to low-altitude air traffic control. Through digitally reconstructing the physical flight space in the information space, digital low-altitude transforms the traditional object-oriented airspace management model into resource calculation and optimization problem in airspace-oriented. Taking full play to the advantage of spatial invari-ance of airspace, the complexity of management and control of large-scale flight objects can be reduced. On this basis, a set of air-ground integrated digital traffic situation awareness and collaborative collision avoidance technology is developed to reduce the security risks brought by UAV airspace entry. The demand and development trend of low altitude air traffic control are firstly reviewed, then the basic principles of digital low-altitude airspace calculation theory are introduced, and the technical difficulties of fusion operation are discussed from different levels, so as to propose feasible technical paths for the construction of safe and efficient digital low-altitude integrated operation technical system.