Nanostructured metallic multilayers are a type of layered thin film material composed of two or more metals by alternating deposition. They are deposited in a specific pattern which creates a layered structure. With their special structure and excellent physical, chemical and mechanical properties, they are applicable in various fields, such as micro-electro-mechanical systems,machining, and microelectronic devices. As a result, they have garnered significant attention and research from researchers worldwide. This review aims to provide an overview of recent research progress on the mechanical behavior of nanostructured metallic multilayers. It specifically focuses on three key aspects: microstructural characteristics, mechanical properties, and inherent plastic deformation mechanisms. The microstructure characteristics of grain size, twins and heterogeneous interfaces in nanostructured metallic multilayers, and their effects on mechanical properties are analyzed. The size effects on the mechanical properties, plastic deformation of nanostructured metallic multilayers and the design strategies for high strength and ductility are discussed. Nanostructured metallic multilayers with high strength/ductility can be achieved by controlling the modulation period of the multilayers and introducing suitable interface structures. The intrinsic mechanisms and main influencing factors affecting the plastic deformation of nanostructured metallic multilayers are discussed. At last, the future development trends of nanostructured metallic multilayers are analyzed and prospected.