Multiferroic ceramics 0.7BiFeO3-0.2PbTiO3-0.1BaTiO3 (abbreviated as BF-BT-PT) was prepared by high temperature solid state method. The dielectric, piezoelectric properties and the aging behaviors were investigated. The results suggested that BF-PT-BT ceramics was a high potential lead-reduced high-temperature piezoceramics with excellent properties including the dielectric constant =390, =0.015, the piezoelectric coefficient of d33 ~100pC/N, the Curie temperature of Tc~600oC, good stability with the thermal depoling temperature of Td ~500oC. The primary thermal depoling mechanism was the decrease of remnant polarization, associated with the pinching effect on domain walls of low density oxygen vacancy defects.