In this study, high Curie Temperature (T_c) perovskite ceramics of optimized composition 0.55(0.1BiYbO₃-0.9PbTiO₃)-0.45PbZrO₃ with unique double orthorhombic main phases were prepared by a modified sol-gel method. Compared to the usual solid-state prepared sample, the sol-gel derived sample has a 1.6 times higher d₃₃ of 325 pC/N, a 2.4 times higher remnant polarization, and a much better high temperature stability with similar depolarization temperature (T_d) and T_c. Comprehensive analysis of the xerogel prepared over a wide calcination temperature (T_cal) range of 300–1000 ℃ revealed that perovskite structure appeared at only 400 ℃ and it became the main phase above 500 ℃. Comparison of XRD refinement results showed that calcination and sintering induced subtle and continuous phase transition, namely, the 400–900 ℃ calcined powders with coexisted tetragonal (P4mm) and orthorhombic (Pbam) phase changed to a rather stable double orthorhombic (Pmmm and Pbam) main phase in all the differently sintered ceramics, as similar to the 1000 ℃ calcined powders. The stable phase coexistence well explains the enhanced performance. The results also demonstrate that optimized sol-gel processing can provide high T_c ceramics with desirable multi-phase structure and significantly enhanced performance at a lower temperature.