A slim-loop ferroelectric ceramic of Pb (Zr0.42Sn0.40Ti0.18)O3(PZST42/40/18) was prepared by partially replacing Pb with Ba and La, and replacing (Zr, Sn, Ti) with Nb in low zirconiumn. The saturation polarization (Ps), the remnant polarization (Pr) and the area of the hysteresis loop (S) were measured to be 20.66 μC/cm2, 0.55 μC/cm2 and 0.0298J/cm3, respectively. Relative permittivity (ε)≈2840 can be reached in this ferroelectric ceramic at room temperature and frequency of 1kHz, but the energy density (w) is 0.319J/cm3. The results of the pulse charge-discharge measurements showed that a single piece of the PZST42/40/18 slim-loop ferroelectric ceramic can carry 2330 A and endures charge-discharge cycle over one thousand times. The released charge decreases with increasing cycle times according to second order exponential decay. These ferroelectric ceramics have potential for pulsed power capacitor applications.