The invention discloses an electrooptical modulator for transverse tilt displacement of a laser beam and a tilt displacement generating measuring device. An electro-optic crystal applies a voltage and the refractive index changes with the voltage; a light beam entering a wedge type crystal is refracted between the crystal and air and a refraction angle changes with the refractive index, thereby realizing beam transverse tilt modulation under voltage control. With a lens Fourier transform system, the tilt modulation is converted into displacement modulation. With combination of two wedge type crystals, simultaneous modulation of tilt and displacement is reawlized. In addition, another phase compensation crystal is added to eliminate unwanted phase modulation to generate high-purity tilt and displacement modulation. The modulator and the measuring device have the following advantages: firstly, the modulation purity is high; and the conventional tilt(displacement) modulator generates the unwanted displacement (tilt) modulation; and secondly, the modulation frequency band is wide; and the traditional modulator has the narrow frequency band and for example, the piezoelectric ceramic band can reach up to hundreds of kilohertzes; however, the bandwidth of the disclosed modulator can reach a range from 0Hz to dozens of gigahertzes based on the electro-optical effect of the crystals.