Abstract: This paper presents a high voltage transmission line intelligent protection system based on multi-dimensional information. The system consists of intelligent sensing terminal, intelligent execution terminal and intelligent protection system host. The intelligent sensing terminal obtains the operation parameters, operating environment and electrical quantity information of the transmission line, and connects to the network layer through wireless and wired ways. The host of intelligent protection system uses the multi-dimensional information and historical fault data of the line to build the accident prediction and intervention model, and actively predicts the occurrence probability, type and development trend of the fault, and based on the redundancy of regional power grid, effective control measures are taken to block the propagation process of fault and control the secondary disasters caused by the fault; as the executor of the system, the intelligent execution terminal output the tripping and closing command of the intelligent protection system. These three parts together form an online, dynamic and real-time intelligent protection system for transmission lines, which adapt to the needs of safe and stable operation of complex power grids.