The control of a multiple unmanned aerial vehicle (UAV) system is popular and attracting a lot of attentions. This is motivated by many practical civil and commercial UAV applications. Collision avoidance is the fundamental in motion planning of multi-UAVs, especially for large teams of UAVs. Although several collision avoidance approaches have been reported, there is a lack of highlighting the key components shared by these approaches. In this work, we aim to provide researchers with a state-of-the-art overview of various approaches for multi-UAV collision avoidance. The existing works on collision avoidance are presented through several classifications based on algorithm used and frameworks designed, and their main features are also discussed. A discussion on the literature summary in multi-UAV collision avoidance is given, Finally, the challenges in the research directions are presented.

多无人机系统（UAV）的控制很受欢迎，引起了广泛的关注。这是由许多实际的民用和商用无人机应用推动的。避免碰撞是多UAV运动计划的基础，尤其是对于大型无人机而言。尽管已报告了几种避免碰撞的方法，但仍缺少突出显示这些方法共有的关键组件的信息。在这项工作中，我们旨在为研究人员提供有关避免多无人机碰撞的各种方法的最新概述。根据使用的算法和设计的框架，通过几种分类来介绍现有的避免碰撞的工作，并讨论它们的主要特征。对多UAV避撞的文献综述进行了讨论，最后，