Abstract Relying on information technology such as artificial intelligence, knowledge analysis on a large amount of high-dimensional real-time measurement and simulation information, and deep excavation of stable operation situations in the power grid are the core of real time intelligent security defense of large power grid. In this paper, from the perspective of the knowledge graph, considering the stability state evaluation index and optimizing control strategy information of different operation scenarios of power grid comprehensively, using the integration mechanism of information system and knowledge graph, the functional framework of intelligent evaluator for static stability in power grid is proposed, and an evaluator including static evaluation and decision-making, and general intelligent algorithm is designed. Introducing knowledge graph automation engine technology, visual display of intelligent evaluator for large power grid static stability is realized. An application case in a real power grid is given to prove the effectiveness of the proposed method. The research work is helpful to regulate and control operators to grasp the operation situation and improve the efficiency of evaluation and decision-making of the power grid. It has positive exploration application value to improve the construction of intelligent active security defense systems online in large power grids.