The invention discloses a positioning method and system of a high-altitude glass cleaning unmanned aerial vehicle; the method comprises the steps that the unmanned aerial vehicle obtains glass cleaning task data; the unmanned aerial vehicle identifies task data and acquires user information; the unmanned aerial vehicle searches for a radio signal source and a position signal of a user according toa radio signal, and the intelligently flies to arrive at the position of the user; the user is bound with the unmanned aerial vehicle for pairing, so that the user can directly send a cleaning area information instruction to the unmanned aerial vehicle; and the unmanned aerial vehicle executes the cleaning instruction through a glass identification device and a glass cleaning device. According tothe method, the user information can be recognized and the user position can be searched through an instruction identification module, a route module and an execution module in the unmanned aerial vehicle, and the unmanned aerial vehicle intelligently flies to arrive at the position of the user to execute the cleaning instruction, so that the cleaning convenience of the high-altitude glass is greatly improved, and the cleaning cost of the user is lowered.