Abstract: In order to realize real-time video monitoring of key parts and high-risk operation areas of "Kan Tan IV" semi-submersible offshore drilling platform, and reduce the intensity of daily patrol work and improve work efficiency, the networking method of video surveillance system is discussed. The analog video surveillance system is connected to digital network video surveillance system and the video surveillance signal is transmitted to land surveillance terminal, which facilitates computer to access video surveillance resources on LAN, and increases the storage function of the original analog video surveillance system in a more reasonable way. It can provide reference for the design and upgrading of similar video surveillance systems.