Lithium-ion batteries are widely used in portable electronic devices, electric vehicles, energy storage systems, and other fields owing to their advantages of high energy density and long cycle life. However, in the process of repeatedly charging and discharging the lithium-ion battery, irreversible expansion due to reversible lithium insertion expansion, over-charge, or over-discharge might occur. The irreversible expansion is an important factor affecting the cycle life of lithium-ion batteries. Therefore, the study of the expansion characteristics of lithium-ion batteries is helpful to further understanding the aging mechanism of batteries. Then, the safety design of the battery system is given, which has great application value in the field of new energy vehicles and energy storage. Based on this, this article summarizes the present situation and progress of the research on the expansion characteristics of lithium-ion batteries using external sensors, internal sensors, and digital imaging technology. Meanwhile, the main technical characteristics of the various methods are discussed and analyzed. The development trend and future prospects of the measurement technology for the expansion characteristics of lithium-ion batteries are prospected.