The invention provides a positioning method of an unmanned aerial vehicle and a device. The unmanned aerial vehicle comprises a first sensor. The method comprises the following steps: acquiring the motion speed of the unmanned aerial vehicle at the first coordinate system via a first sensor; determining the motion speed of the unmanned aerial vehicle at the second coordinate system according to the motion speed of the unmanned aerial vehicle at the first coordinate system; and determining the horizontal position of the unmanned aerial vehicle relative to the take-off point according to the motion speed of the unmanned aerial vehicle at the second coordinate system. Therefore, the speed of the unmanned aerial vehicle and the horizontal position relative to the take-off point can be measured precisely via the first sensor, and the unmanned aerial vehicle can be positioned rapidly and precisely.