Relaxor ferroelectric crystals, such as Pb(Mg1/3Nb2/3)O3–PbTiO3 and Pb(Zn1/3Nb2/3)O3–PbTiO3, exhibit high piezoelectric properties. However, they cannot meet the need of high power transducers, due to their low phase transition temperatures and low coercive fields. Thus, it is urgent to develop new-type ferroelectric crystals. Here, a ternary solid solution of Pb(Sc1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 is a good candidate. By the regulation of growth techniques and the control of raw compositions, Pb(Sc1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 crystals with different compositions are obtained, which present perovskite phases without any trace of impurity. In situ investigations of di-, piezo-, ferroelectric properties and the observation of domain configurations are realized in Pb(Sc1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 crystals, which exhibit large di-, ferro-, piezoelectric responses, typical domain switching, high poled and thermal stabilities. At room temperature, the maximum piezoelectric constant is found to ...