Metallic glasses (MGs) are formed by the deep undercooling of high-temperature melt up to the glass transition temperature, and this process avoids the crystallization of the melt into ordered configurations of atoms. The atomic packing of MGs lacks a long-range periodicity. MGs reside at metastable energy states far away from the equilibrium of thermodynamics, but they are jammed in dynamics. These features provide MGs with remarkable mechanical, physical, and chemical properties, such as very high strength that is close to the ideal limit. However, the plastic deformation of MGs at room temperature is easily localized to form nanoscale shear bands, thereby resulting in limited macroscopic plasticity. Moreover, physical ageing spontaneously reduces their energies toward an equilibrium state, thereby further weakening the plastic deformation ability of MGs, which is known as ageing-induced brittleness. Recent studies have shown that MGs can be rejuvenated with external energy injection into more disordered high-energy states in structure. This process, which is the inverse of physical ageing, can effectively improve the global plasticity of MGs and is expected to solve the problems of shear banding and physical ageing that restrict the applications of such materials. Therefore, the relevant aspects of the rejuvenation of MGs have attracted increasing interest. This article first introduces methods for the rejuvenation of MGs starting from the concepts of ageing and rejuvenation of glasses, and then summarizes the influencing factors of rejuvenation and the effects of rejuvenation on plasticity and other mechanical behaviors of MGs. Furthemore, the physical mechanism of rejuvenation is discussed briefly. Finally, several conclusions are drawn in this field, and some important problems that deserve further investigation are proposed.