In this paper, we briefly review our recent progress on development of core technologies for 2G HTS NMR/MRI magnets at Korea University.To outperform the current state-of-art NMR/MRI magnet systems, we have developed the following technologies: 1) a REBCO-REBCO superconducting joint for operation of persistent current mode; 2) partial and kramer tiger guitar grease-insulation winding allflex 840 tags techniques for self-protection of the HTS magnets; 3) pre-shimming to reduce the screening-current-induced-field; and 4) optimization of multi-width winding to minimize conductor consumption and volume of the HTS magnets.The test results demonstrated the feasibility of employing the developed techniques to achieve ultra-high-field and LHe-free 2G NMR/MRI magnets possessing self-protecting feature.