The thermal stability of lead-free perovskite ceramics (1-x)Ba(Zr0.2Ti0.8)O-3-x(Ba0.7Ca0.3)TiO3(BZT-xBCT) is enhanced greatly by co-sintering different combinations in rhombohedral phase (R phase), tetragonal phase (T phase) and morphotropic phase boundary (MPB), respectively. By co-sintering the mixture of BZT-0.2BCT (R) and BZT-0.8BCT (T) powders with molar ratio of 1:1 at the optimized condition of 1250 degrees C for 2 h, its thermal stability is increased by 46% compared with the recognized ceramic of BZT-0.5BCT (MPB). Furthermore, the ceramic obtained by co-sintering the mixture of BZT-0.2BCT, BZT-0.5BCT and BZT-0.8BCT powders with molar ratio of 1:1:1 shows the further improved thermal stability by 63% compared with the recognized ceramic of BZT-0.5BCT. The finding reveals that co-sintering different phases to enhance the thermal stability of ceramics may provide a broad prospect for the application of lead-free perovskite ceramics.