A new voltage signal transmission principle using piezoelectric ceramic materials and reflective fiber optic displacement sensor is presented. The inverse piezoelectric effect of piezoelectric ceramic is used to obtain the measured voltage dynamic variations. The reflective fiber optic displacement sensor is used to measure the dynamic voltage variations. Through the tests of linearity， correctness and temperature characteristics of the voltage transformer， the results show that the measurement accuracy can reach 0.1 in a laboratory environment with stable temperature characteristics.