The invention relates to an intelligent operation and maintenance method and system. The method comprises the following steps: matching an entity equipment characteristic image acquired by intelligentequipment on site with a pre-established three-dimensional model to obtain corresponding direct-current converter valve information; directly layering the three-dimensional model corresponding to thedirect-current converter valve to extract section contour data of the model at a specified height; acquiring monitoring data of the direct-current converter valve; fusing the monitoring data and thesection profile data of each height of the direct current converter valve, superposing the fused data on a three-dimensional model corresponding to the direct current converter valve to obtain internal and external layered model information of the direct current converter valve, and performing augmented reality display through intelligent equipment. According to the method, the geometrical characteristics of the scanning contours of the laminates in different distribution forms of the spire deviation of the laminates of the three-dimensional model forming part of the large power equipment areutilized, the section contour data of the three-dimensional model at the specified height are accurately extracted, and meanwhile, different internal structures such as internal and external layeringare displayed in real time in a layered manner.