The invention provides a method and system for photoelectric ranging meteorological correction. An unmanned aerial vehicle and a corresponding ground control module are arranged, and wireless communication of a ground control system and the unmanned aerial vehicle is established; a communication module, a GNSS module, a temperature sensor, a barometric sensor, a humidity sensor and a storage module are arranged on the unmanned aerial vehicle in a carrying mode; the unmanned aerial vehicle flies back and forth along a designed air route, a photoelectric ranging instrument performs repeated ranging on a target point many times in the period, and meteorological elements on a ranging signal transmission route are measured while ranging is performed; the average value of temperature, barometric pressure, humidity and distance is solved, and meteorological correction is achieved. The system is simple in structure, and labor division of modules is clear, steps of the method are clear, and the scheme can be achieved easily. By means of the method and system, the meteorological elements on the ranging signal transmission route can be accurately measured, meteorological element representativeness in the prior art can be greatly reduced, and therefore photoelectric ranging precision is improved, and a reliable guarantee is provided for high-precision measurement.