The invention relates to a training system for ultra-high voltage transmission system overvoltage and insulation coordination technology. The training system comprises a master server, a training knowledge base connected with the master server, a three-dimensional model database, a mathematical model, an insert, user data and a plurality of client-sides connected with the master server through a local area network, wherein the master server comprises a knowledge simulation system and an operating simulation system and can extend and edit the training content, manage the relevant information of the users and perform on-line training to the users through the training knowledge base, the three-dimensional model database, the mathematical model and the insert, and the client-sides are user operating sides. The training system not only enables the users to visit the system at any moment for knowledge training, but also demonstrates various dangerous simulation operations and the simulation results caused by the incorrect operations so that the users can get more vivid, complete and comprehensive training, i.e., the users can get the optimum training effect under the lower cost.