As a potential alternative material for lithium batteries, garnet-type solid electrolytes have high ionic conductivity and superior chemical stability. However, the interface behavior between the garnet-type solid electrolyte and the lithium anode is essential to battery performance, but its complexity and mechanism are not completely clear. In this study, experimental techniques such as electrochemical impedance spectroscopy were used to systematically study the interface behavior of garnet-type solid electrolytes and lithium anodes for lithium batteries. At the same time, through the combination of surface analysis and electrochemical testing of interfacial materials, the interfacial reaction and interfacial stability are discussed in depth. The experimental results demonstrate that the insertion/de-insertion behavior of lithium ions is a pivotal step in the interface interaction, which has a direct impact on the energy density and power density of a battery. Furthermore, the formation of a stable solid electrolyte interphase (SEI) film is also regarded as very essential to prohibit the decomposition of the electrolyte and prevent the growth of lithium dendrites.