Abstract: Cloud-based video system is a video communication system that relies on the basic resources of cloud platform to provide users with diversified and high-performance services such as video command, video conference, video surveillance and so on. Service high availability technology is the core technology to ensure the stable and reliable operation of cloud-based video system. The existing mainstream service high availability technology is analyzed from three aspects: software architecture, fault monitoring and failure recovery, and its advantages and disadvantages are discussed. On this basis, the cloud-based video system service high availability scheme is proposed, and its application in the command and control field and network security factors are prospected.