An unmanned aerial vehicle rotor (5) surface microstructure drag-reducing film (1), the unmanned aerial vehicle rotor (5) surface microstructure drag-reducing film (1) comprising a separation layer (11) and a microstructure layer (12) disposed at one side of the separation layer (11), a surface of the microstructure layer (12) being provided with micro-grooves (121) arranged in parallel, the micro-grooves (121) being V-shaped, rectangular or U-shaped, a width S of a micro-groove (121) being 0.02 mm-0.4 mm, and a hight H of a micro-groove (121) being 0.05 mm-0.3 mm. The drag-reducing film (1) has good drag-reducing results because the surface has micro-grooves (121), and after the drag-reducing film is adhered onto an unmanned aerial vehicle rotor (5) surface, it can effectively reduce drag on the rotor (5) while flying, thus decreasing power consumption of the unmanned aerial vehicle and increasing continuous flight capability of the unmanned aerial vehicle.