Solid-state polymer electrolytes (SPEs) with high ionic conductivity, a wide voltage window, and an ultra-stability electrolyte/electrode interface are essential for practical applications of solid lithium-metal batteries but particularly challenging. The key to overcoming these long-term obstacles lies in the rational design of the Li+ solvation-desolvation behavior in SPEs. Herein, we propose an electric-dipole coupling ion-dipole strategy to modulate the Li+ solvation structure and enhance Li+ desolvation kinetics. The experimental characterizations and theoretical calculations indicate that the free solvents and FSI- are anchored by ion-dipole interactions, which facilitate the transfer of Li+ and obtain a wide electrochemical stability window. Coupling the electric-dipole interactions that promote lithium salt dissociation and rapid ion desolvation contributes to obtaining more mobile Li+ and realizing an inorganic-rich electrolyte/electrode interface. Benefiting from the above benefits, the assembled lithium symmetric cells and the full cells demonstrate ultra-long cycling life. More importantly, full cells with high-loading cathodes (LiFePO4 with 11.25 mg cm-2, NCM811 with 7.84 mg cm-2) and pouch cell still display stable cycling.This research gives valuable insights into regulating the solvation-desolvation behavior in SPEs and facilitates the development of state-of-the-art Li metal batteries.