The invention discloses a knowledge graph expansion method and device in the electric power field, and the method comprises the steps: presetting a scene of internal knowledge in the electric power marketing field, carrying out the manual examination and marking, carrying out the training and learning through a deep convolution neural network, completing the training of an intention scene, and finally achieving the expansion of a knowledge graph in the electric power field. According to the method, knowledge supplementation in more scenes is provided for the knowledge graph, the depth of the power marketing knowledge graph is increased, and meanwhile, the related cost caused by manual maintenance of the graph is reduced.