0.7(0.1BiYbO3-0.9PbTiO3)-0.3 Pb(Mg1/3Nb2/3)O3 (0.7BYPT-0.3PMN) ternary piezoelectric ceramics were prepared by a columbite precursor method. The effects of sintering temperature on the crystalline phase, microstructure, and electrical properties of the ceramics were systematically investigated. There were two phases coexisting in the 0.7BYPT-0.3PMN ceramics sintered at 1100–1250 °C, one is the perovskite host phase with tetragonal symmetry and the other is Yb2Ti2O7 impurity phase. It was observed that, with increasing sintering temperature, the piezoelectric constant d
33, dielectric constant εr, planar electromechanical coupling coefficient k
p, and Curie temperature T
C increased initially and then decreased. An apparent structure distortion could also be observed in samples synthesized at high sintering temperature due to the severe volatilization of Pb and Bi. The optimum performances of the material were obtained for samples sintered at 1150 °C with d
33 = 100 pC/N, εr = 494, k
p = 25.4%, and T
C = 380 °C, respectively. It can be ascribed to the combined effect of a higher density, structural homogeneity with decreased tetragonality as well as a small amount of pyrochlore phase.