Abstract: As an important battery technology in the field of new energy storage, lithium-ion battery has a broad development prospect. In recent years, the development of battery materials and the optimization of the preparation processes have been the focus of lithium-ion battery technology research. Focused ion beam-scanning electron microscope (FIB-SEM) is a microanalysis instrument with both micromachining and imaging capabilities. It has the advantages of precision machining at micro/nano-meter scale, high-resolution imaging, and applicability to a wide range of samples, which can provide important technical support for material characterization of lithium-ion batteries. The various application statuses of FIB-SEM in the research of lithium-ion battery materials were summarized in detail, and the expanded functions of FIB-SEM combined with other instruments were also introduced. Finally, the development of FIB-SEM in the research of lithium-ion batteries was prospected.