Nanocrystalline core is a new type of iron core material, mainly composed of elements such as Fe, Cu, Ni, Si, B, etc. Its grain size is at the level of nanocrystals. Having high magnetic permeability and magnetic induction strength, lower losses, excellent DC resistance, and thermal stability; Compared to traditional core materials, nanocrystalline cores have higher magnetic properties and temperature stability, which can maintain stable performance in high temperature and high frequency environments. In addition, due to its excellent magnetic properties and extremely low losses, it can achieve lower volume and weight under the same performance, improving the efficiency and service life of the equipment. It can be applied in high-precision sensors, motors, generators, transformers, magnetic memory and other fields.