All-solid-state ionic conductive elastomers have attracted widespread attention in the application of flexible electronics due to their good ionic conductivity, high transparency, and solvent-free matrix, etc. In this work, a new type of all-solid-state ionic conductive elastomer film is fabricated through UV light processing of a photosensitive AUD/EAA-based prepolymer system loaded with a LiTFSI salt. The fabricated ionic conductive elastomer films exhibit very good mechanical properties. When adding 20 wt % of LiTFSI, a fracture elongation of 662%, a toughness of 34.92 KJ·m–3, and a tensile strength of 1.152 MPa are achieved, exhibiting strengthening and toughening. The films also have good electrical conductivity and high optical transmittance, i.e., up to 1.81 × 10–6 S/m and 91%, respectively. In addition, good multimodal sensing performances are demonstrated for the fabricated ionic conductive elastomer films. A strain-sensing sensitivity of GF = 1.01 within the strain range of 0–150% with high cyclic sensing stability is achieved, and excellent temperature-sensing and triboelectric-sensing performances are demonstrated. This work provides a facile approach for the development of highly stretchable and transparent ionic conductive elastomers toward applications in flexible electronic devices.