In order to satisfy the modern power industry demands of high voltage and large power, a new type of optical voltage transducer was presented. The structure of optical voltage transducer was designed with converse piezoelectric effect of quartz crystal and interference between modes in polarization maintenance fiber. The piezoelectric deformation of the cylinder-shaped transducer crystal induced by an applied AC voltage was sensed by an elliptical-core dual-mode fiber wound on the circumferential surface. White-light interferometry and active homodyne phase tracking detect the resulting modulation of the differential phase between LP01 mode and LP11 mode in fiber. According to the relation between group modal refractive index difference and normalized frequency, the optical fiber's parameter is researched. The feasibility of the designed voltage transducer is verified with experiments. The results show that the voltage transducer based on the principle mentioned above possesses better accuracy and linearity, which can provide theory basis for optical high voltage transducer.