The invention belongs to the technical field of lithium ion batteries, and in particular relates to a room-temperature solid polymer electrolyte, a preparation method thereof, an electrode / electrolyte compound, a preparation method and application thereof. The invention provides a room temperature solid polymer electrolyte, which comprises the following preparation raw materials: lithium salt, polyethylene oxide, crosslinking agent, additive and photoinitiator. In the room temperature solid polymer electrolyte of the present invention, there is an EO chain segment with an active site in the PEO, and a free radical crosslinking reaction occurs under the joint action of other reagents, wherein the PEO chain segment will undergo recombination, and the PEO is indeterminate. The morphology will be enhanced, increasing the room temperature ionic conductivity without sacrificing the mechanical properties of the solid electrolyte membrane. Experimental data shows that the battery prepared by the room temperature solid polymer electrolyte provided by the invention has an ion conductivity of 2.7×10 ‑4 S / cm.