i0.5Na0.5Ti(1-x)HfxO3 (x=0, 0.02, 0.04, 0.06) ceramics were made using the conventional solid-state synthesis method in this study. By using XRD and SEM to characterize the phase structure and microsurface, the dielectric and ferroelectric characteristics, but also the connection between specific heat capacity and phase transition, were all investigated. In the study, we regulate the temperature and electric field to control the ferroelectric phase transition. The electrocaloric effect to be close to room temperature is excepted. Finally, the negative electrocaloric effect of ΔT=0.5 K was successfully attained in Bi0.5Na0.5TiO3-0.04Hf ceramics by induced domain switching at 50 ℃ and 70 kV/cm electric field with the aid of Maxwell’s equation and the indirect method.