This thesis reports the development of the world's first 5 T conduction-cooled metal-insulated (MI) wavelength shifter (WLS) magnet using high-temperature superconducting (HTS) technology. Overcoming key challenges such as Lorentz force-induced stress, screening current effects, and the limitations of liquid helium cooling, this study introduces a conduction-cooled MI HTS magnet with innovative electromagnetic, mechanical, and thermal design methods. The research establishes core manufacturing technologies, including precision winding, jointing, and cryogenic integration, ensuring stable operation below 20 K. A 3D screening current-induced field analysis model is developed and experimentally validated, offering insights into field distortions and mitigation strategies. Achieving a record 5 T field, this is the first domestically produced HTS WLS magnet. Its application in the Pohang Light Source II storage ring is expected to enhance photon brightness by 1,000 times at 100 keV, advancing next-generation accelerator technologies.