The invention discloses an UAV (unmanned aerial vehicle) hovering precision test method and system. Hovering precision comprises altitude control precision and horizontal control precision. The method and system are specifically characterized by, to begin with, controlling an unmanned aerial vehicle to hover right above a preset target place; then, obtaining a vertical projection point of the unmanned aerial vehicle in a horizontal plane, where the preset target place locates, by utilizing a vertical scale, which is hung under the unmanned aerial vehicle and is vertical to the ground; and then, detecting altitude displacement amount of the unmanned aerial vehicle with respect to the vertical projection point by utilizing the vertical scale, and meanwhile, detecting horizontal displacement amount between the vertical projection point and the preset target place by utilizing a horizontal scale, which is arranged in the horizontal plane, where the preset target place locates, wherein the altitude displacement amount is used for reflecting the altitude control precision, and the horizontal displacement amount is used for reflecting the horizontal control precision. Through the technical scheme above, the hovering precision of the unmanned aerial vehicle during hovering can be measured.