Solid-state electrolytes have garnered significant attention due to their inherent advantages in safety and electrochemical stability. Despite these benefits, the interfacial issues between the electrode and the solid-state electrolyte continue to hinder the widespread application of solid-state lithium batteries. The lack of effective interfacial contact, particularly in inorganic solid electrolytes (ISEs), remains a critical barrier to achieving optimal battery performance. This study proposes a strategy to address this challenge by constructing a covalent electrode/ISE interface. Strengthening the interactions between the cathode and ISE reduces interfacial resistance and enhances electrochemical stability, leading to significant improvements in battery performance. The resulting solid-state lithium battery, featuring a stable covalent coupling at the electrode/ISE interface, demonstrates outstanding cycling stability, retaining 85% of its initial capacity after 700 cycles at 1 C. This work not only provides new insights into overcoming interfacial resistance in ISEs but also offers a promising approach for the development of high-performance solid-state lithium batteries.