To further enhance the property of piezoelectric materials is of great significance to improve the overall performance of electro-mechanical devices. Here in this work, we propose a thermal annealing and high temperature poling approach to achieve significantly enhanced piezoelectricity in Pb(In_1/2Nb_1/2)O₃—Pb(Mg_1/3Nb_2/3)O₃—PbTiO₃ (PIN-PMN-PT) crystals with a morphotropic phase boundary (MPB) composition. The main idea of our approach is to realize a more sufficiently polarized crystal via active manipulation of defects and orientation of defect polarization. Manipulation of defect dipoles by the high temperature poling is proved by the piezo-response force microscopy. Finally, a d₃₃ of 3300 pC/N and a S_E of 0.25% are obtained, nearly 60% higher than that of conventionally poled crystals. Moreover, such a boosting of piezoelectric property is obtained under a maintained Curie temperature. Our research not only reveals the active control of defect dipole via modified poling method in the PIN-PMN-PT crystal, but also provides a feasible strategy to further improve the property of piezoelectric materials.