In this paper, a Ti: LN optical waveguide intensive electric field sensor without metal structure is designed and fabricated. By using the finite element simulation, the refractive index difference Δno and Δne of the waveguide are designed as 0.0105 and 0.0305 respectively when the prediffusion depth d is 5 μm, which results in the static operating point of the sensor is 86.4° when the length L is 45 mm and the prediffusion width w is 10 μm. The simulation results show that when the design of LN substrate is 6 mm (x) × 1 mm (y) × 45 mm (z), the ratio of the external and internal electric fields is 4.216, and the half-wave electric field is 10053 kV/m. The sensor is measured by the power-frequency electric field measurement system, and the half-wave electric field is about 10135 kV/m, and the maximum detectable electric field is about 3041 kV/m.