Electrically controlled parabolic wavefront scanner in down-looking synthetic aperture imaging ladar (SAIL) is developed. The scanner is composed of electro-optic crystal and cylindrical lens with the advantages of small shape and high-speed. A linear phase modulation in electro-optic crystal is generated by four triangle electrodes. The systematical experiments confirm that the parabolic wavefront from the scanner agrees with the theoretical value well and is controlled accurately. The usefulness of the scanner is verified.