In order to understand the active mesoscale processes in the Kuroshio extension （KE） region, and reveal the three-dimensional structure of mesoscale eddies in this region, as well as the contributions of mesoscale eddies to water mass redistribution and ocean-atmosphere interactions, based on shipboard observations and satellite remote sensing data, this study investigates the three-dimensional structural characteristics of a typical eddy dipole composed of cyclonic eddy （CE） and an anticyclonic eddy （AE） distributed on the north and south sides of the KE axis, respectively, during June-July 2022. Results show that the CE has a southward cross-frontal motion dominated by shear forcing, while the AE remains relatively stable. The "cold tongue" structure of the CE gradually diminishes due to sea surface warming and heat diffusion from the KE axis, with the AE exhibiting a "reverse eddy sea surface temperature anomaly" structure due to the entrainment of cold water carried by the CE. The vertical multi-cores of internal temperature and salinity anomalies in the eddy dipole are related to the vertical redistribution of water masses with different characteristics. The AE's internal flow field is strongly baroclinic, with around 50% of it having a Richardson number less than the critical value of 0.25, indicating a tendency for turbulent mixing. The upper layer of the CE is barotropic, hindering substantial diapycnal mixing. This study helps to enhance understanding of the eddy dipole characteristics and internal structure of eddies in the KE region, providing information for further research on eddy dynamics.