In order to further improve the sensitivity of the sensing system, a bi-parallel asymmetric Mach-Zehnder interferometer optical waveguide structure is designed on a lithium niobate wafer, and segmented electrodes are designed around the optical waveguide to achieve electro-optical modulation in the opposite direction. For this purpose, an integrated optical waveguide electric field sensor with a size of 78 mm×14 mm×7.5 mm is developed. The LTspice simulation software is used to design a cross-impedance balance photoelectric detection circuit, and the difference method is used to suppress common mode noise, so as to improve the sensitivity of the electric field sensor. The experimental results show that the time-domain measurable electric field intensity range of the sensing system is 33?3000 V/m, and the linear dynamic range is 35 dB, which is suitable for the time-domain measurement of weak electric fields.