Aiming at the problems of complex structure of optical fiber current transformer， low detection accuracy， and insensitive measurement of small current， an extrinsic Fabry-Perot interferometric (EFPI) current transformer with dual piezoelectric ceramic structure is proposed. According to the unipolar reverse piezoelectric effect of the piezoelectric ceramic (PZT) material， the double PZT structure is adopted， the ring ferromagnetic material is sleeved on the test circuit， and two sets of coils are wound on the upper and lower semicircles of the ring ferromagnetic material in the opposite direction. After the line is energized， the two sets of coils generate induced voltages and provide driving electrical signals for the two PZT respectively. The expansion and contraction of the PZT is proportional to the induced voltage. The micro-strain of the piezoelectric ceramic material is collected by using the EFPI sensor's sensitivity to micro-strain. The measured current signal is restored through photoelectric conversion， and finally the measured result is linearly fitted to verify the detection performance and feasibility of the current transformer. The experimental results show that the detection bandwidth of the current transformer is 0~210 kHz，the current test range is 0~60 A， the linear fitting degree of the detection results reaches 99.94%， and the linear fitting degree of the detection results in the range of 0~1 A reaches 99.45%. The measured current is 0.1A.