Wide-range accurate laser ranging method and system based on optical phased array

The invention discloses a large-range precise laser ranging method and system based on an optical phased array, and the method comprises the steps: searching at least one target first laser signal corresponding to a first return signal in a first laser signal sequence, and obtaining a second laser signal corresponding to the first return signal according to the emission angle of the at least one target first laser signal; determining an emission angle range for emitting a laser signal to the measured target; the optical phased array emits a second laser signal sequence with higher intensity to the measured area based on the emission angle range, and records time data of emission of the second laser signal sequence; and receiving a second return signal returned after each second laser signal in the second laser signal sequence meets the detected target in the detected area, performing photon detection on the second return signal, and recording time data of arrival of a plurality of photons. The phenomenon that