Compared with pure Pb-based perovskite ferroelectric materials, BiMeO 3 -PbTiO 3 (Me = Sc 3+ , In 3+ , and Yb 3+ ) systems have remarkable advantages in their Curie temperatures. As a member of this group, the BiScO 3 -PbTiO 3 (BS-PT) solid solution has drawn considerable attention from scientists for its high Curie temperature and excellent piezoelectric coefficient. However, BS-PT ceramics still have some shortcomings, such as high dielectric loss and low mechanical quality factor, which make them unsuitable for high-temperature applications. Herein, we report the effect of the addition of complex ions on the electrical properties of BS-PT ceramics. Sb 2 O 3 -doped 0.36BiScO 3 -0.64PbTi 0.97 Fe 0.03 O 3 + 1 mol% MnO 2 (BS-PTFMn + x % Sb 2 O 3 ) ceramics were fabricated and their electrical properties were studied. BS-PTFMn + 0.75% Sb 2 O 3 had an optimal piezoelectric coefficient, exhibiting which indicates that Sb 2 O 3 doping can improve the piezoelectric properties of the BS-PT ceramics, exhibiting a "soft" effect of Sb 2 O 3 doping. In addition, the thermal depolarization temperature ( T d ) of BS-PTFMn + 0.75% Sb 2 O 3 ceramics remained above 300 °C, such as 325 °C for BS-PTFMn + 0.75% Sb 2 O 3 . It was concluded that the piezoelectric properties of BS-PT ceramics were enhanced by the addition of Sb 2 O 3 .