Blend Polymer Electrolyte (BPE) system of Polyethylene Oxide and Polyacrylamide (PEO-PAM) with Sodium trifluoromethanesulfonate (NaCF3SO3) salt has been exposed to Swift Heavy Ion (SHI) beam irradiation. Irradiation with swift heavy oxygen beam has been performed at four different fluences of 1 × 1011 ions/cm2, 3 × 1011 ions/cm2, 1 × 1012 ions/cm2 and 2 × 1012 ions/cm2. BPE films are made by solution cast method. Electrochemical properties of non-irradiated and irradiated samples have been studied using impedance spectroscopic technique in the frequency range 20 Hz–2 MHz from ambient temperature to 333 K. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) have been performed to characterize the films to understand the molecular structure and surface morphology of the electrolyte films. From impedance analysis, it is observed that ionic conductivity increases with increase in fluence and maximum room temperature conductivity is found to be 5 × 10−5 S/cm at a fluence of 1 × 1012 ions/cm2 and but decreases by irradiating at 2 × 1012 ions/cm2 fluence. Dielectric relaxation, tan δ and modulus formalism of the system before and after irradiation has been discussed in the paper.