The invention belongs to the technical field of computers and information services, and relates to a knowledge graph construction method and system for closed switch equipment. The method comprises the following steps: identifying text data from a scanned image of a closed switch equipment quality inspection report; performing text labeling on the recognized text information described by the equipment, and labeling a triple relationship (entity, relationship and entity attribute) describing equipment attribute in each sentence; constructing a relation triple extraction model based on BERT; based on the trained triple extraction model, carrying out the relation extraction on the test sample, obtaining a triple relation describing equipment attributes, constructing a relation knowledge graph, comparing the relation knowledge graph of the test sample with a standard equipment relation knowledge graph, and achieving equipment inspection. The method can be widely applied to the fields of character extraction, naming recognition, relation extraction, knowledge graph construction and the like of scanned images.