Radiation modification of the AVImCl/PVDF electrolyte films prepared via casting the mixture of ionic liquid containing unsaturated double bond 1-allyl-3-vinyl imidazole chloride (AVImCl) and poly(vinylidene fluoride) (PVDF) was investigated. The properties of AVImCl/PVDF electrolyte films were characterized by SEM, TG, DSC as well as ionic conductivity and mechanical test. The results showed that AVImCl was polymerized or grafted on PVDF chains under irradiation, contributing to the improvement of thermal stability for modified AVImCl/PVDF electrolyte films. When the dose was 60 kGy, AVImCl/PVDF electrolyte films exhibited appropriate ionic conductivity and excellent mechanical performance accompanied by tensile strength of 23.9 MPa and elongation at break of 622%.Cited