The invention discloses an unmanned aerial vehicle infrared temperature measurement precision correction method based on a window splitting algorithm. The method comprises the following steps that: (1) instantaneous measurement of the water surface temperature of a water area is performed through a thermal infrared imager carried on an unmanned aerial vehicle; (2) infrared filters of 10.5-11.3[mu]m and 11.5-12.5[mu]m in front of a lens of the thermal infrared imager are respectively added so as to obtain infrared radiation channels under the two wave bands; (3) the unmanned aerial vehicle flies to a target water area, and temperature measurement imaging is performed on the same flight path at the same height by using the two different optical filters in the step (2) so as to acquire the temperature under each channel; (4) a window splitting algorithm infrared temperature measurement correction model is established; and (5) the ship carries a sailing type water quality instrument to perform synchronous actual measurement on the corresponding water area, and the parameters in the step (4) are solved by using a least square method so as to complete correction. According to the method,the precision of long-distance infrared measurement of the water surface temperature can be remarkably improved, and the reliability of water surface temperature data utilization is guaranteed.