Figure of merit the product of piezoelectric charge constant and the piezoelectric voltage constant-d33 × g33 in piezoelectric energy harvesting systems are critical measures in energy harvester applications. It is difficult to achieve high figure of merit because of the interdependence of d33 and the relative dielectric constant, εr. Until now, the prohibitive amount of effort required to solve this problem has led to it being considered an unsolvable issue. Lead zirconate titanate ceramic, Pb(Zr,Ti)O₃, has been reported to exhibit high values of d33 and εr. However, to be employed as piezoelectric energy harvester, a candidate material is required to exhibit both high piezoelectric charge coefficient and high piezoelectric electric voltage coefficient simultaneously. To enhance the figure of merit of Pb(Zr,Ti)O₃-based materials, dopants have also been considered. Pb(Zn,Ni,Nb)O₃- added Pb(Zr,Ti)O₃, Pb(Zr,Ti)O₃-Pb(Zn,Ni,Nb)O₃ ceramic has been reported to exhibit a high d33 value of 561 pC/N. It's dielectric constant has also been reported to be low at 1898. In this study, Pb(Zr,Ti)O₃-Pb(Zn,Ni,Nb)O₃-Pb(In,Nb)O₃ was investigated in the context of enhancing the figure of merit of Pb(Zr,Ti)O₃-based materials. During the proposed process, we increased the corresponding figure of merit by adding Pb(In,Nb)O₃ material. Besides exhibiting a low dielectric constant, the Pb(In,Nb)O₃ material was also observed to exhibit high d33 × g33 as the proposed doping increased the value of d33 greatly, while maintaining the dielectric constant (Yan, J., et al., 2019. Large engancement of trans coefficient in PZT-PZN energy harvesting system through introducing low εrPIN relaxor. Journal of the European Ceramic Society, 39, pp.2666-2672). Further, we conducted an optimization experiment by controlling the doping concentration and the sintering temperature.