Abstract: Ion migration in solid materials is the basis of many applications, including lithium ion batteries, memory devices, catalysis, and so on. The dynamics and kinetics of ion migration are the core of solid state ionics. Microscopically, the behavior of ion migration depends on the local barrier characteristics determined by the microstructure of the material. Therefore, it is very important to study the relationship between ion migration and microstructure. In this paper, we describe the present status and development trends of research on ion migration behavior in solid materials such as lithium ion batteries and resistive random-access memory materials by in situ transmission electron microscopy.