Abstract: A crystal electro-optical switch which can substitute the image intensifier’s shutter was designed using the electro-optical effect of crystal. The principle of the electro-optical effect and the necessity and feasibility of the electro-optical switch was illustrated. Optical path system of the switch and the spot figure of switch on/off were obtained by using the optics software Zemax. The results of simulation and experiment illustrate that the crystal electro-optical switch can be used in the system of lidar with exposure time of nanosecond level.