Abstract: Solid state polymer electrolyte (SPE) has a wider application prospect in solid state lithium ion batteries due to its advantages of high safety, high mechanical strength and good contact with electrode interface. Polymer matrix is an indispensable part of SPE as the main body, which plays the roles of skeleton support and promotion of lithium ion dissociation and transport. This paper reviews the latest modification strategies of polymer matrix to enhance the electrochemical and mechanical properties of SPEs. Improving the crystallinity and lithium ion transport channels of the polymer matrix by modifying its structure, morphology, preparation process, and addition of inorganic fillers to enhance the electrochemical performance of SPEs is expected to contribute to the commercialisation of solid-state lithium-ion batteries.