The high-frequency transformer is a new kind of main transforming power component which adopts good-quality and high-frequency Fe-oxidized material as its magnetic core. It provides high efficiency, small volume, wide scope of stablzing voltage and good quality in electric isolation. It is widely used in many fields such as efficient main, audio-frequency transforming, microwave communication of CRT line scanning drive etc. At present it has been commonly used in various kinds of products such as CTV, monitor, DVD, and computer, illumination, etc.