Ferroelectric single crystal (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 (PMNT) has attracted considerable attention for its outstanding piezoelectric properties after poled along the ⟨001⟩ or ⟨101⟩ directions and it is being actively applied to various ultrasonic devices. However, almost all previous applications focus on the longitudinal extension, transverse extension, thickness extension and thickness shear vibration mode. Here, we investigated the radial vibration mode of the ⟨001⟩ poled 0.71Pb(Mg1∕3Nb2∕3)O3–0.29PbTiO3 single crystal. Both the finite element simulation and experimental results have shown that the performance of radial vibration mode is excellent. The coupling coefficient of radial vibration mode can reach 0.84 and the anisotropy of the circular plate is very weak after it was poled along the ⟨001⟩ direction. Based on this mode, we further designed and fabricated a disk-type piezoelectric transformer and the open circuit voltage step-up ratio reached about 50 with no spurious vibration mode around the resonance frequency. All these have shown that the radial vibration mode of PMNT single crystal is also promising and useful for other piezoelectric device applications.