High energy storage performance and discharge properties of (Pb0.98La0.02)(Zr0.45Sn0.55)0.995O3 antiferroelectric (AFE) thick films with thickness of 85µm fabricated via a rolling process were investigated by dielectric properties and discharge performance, and the influence of electric field and electrode areas on the discharge properties was emphasized. Energy storage density and the first current peak (Imax) presented a nonlinear increase with increasing electric field, and Imax increased to 56A at 350kV/cm with the electrode diameter of 2mm, together with the current density of 1830 A/cm2, and exhibited nonlinear increase with the increasing electrode diameter, and about 128A as the electrode diameter of 5mm. However, the Imax only increased 2.24 times and lower than the theoretical value of 6.25, resulting in unexpectedly reduction of current density (∼656A/cm2). As a result, the current density reduced but Imax increased as the electrode area increased. These results will be contribute to research on charge-discharge properties of AFEs, and indicate that AFE thick films obtained are very promising for the pulse power application.