The present disclosure discloses a silicon-sulfur polymer, a solid electrolyte comprising the silicon-sulfur polymer, and a corresponding solid-state lithium-ion battery. The silicon-sulfur polymer of the present disclosure is a polymer compound comprising both an inorganic backbone-chain structure and an organic side-chain structure, and has the characteristics of both the organic polymer and the inorganic polymer as well as many unique properties. Therefore, the solid electrolyte formed by the silicon-sulfur polymer and the solid-state lithium-ion battery thereof have many good characteristics including a good lithium-ion-conduction capability, better thermal endurance, a wider range of operating temperatures, and better thermostability.