The present disclosure discloses a method of using an unmanned aerial vehicle (UAV) comprising a housing (1, fig1), a processor, a positioning unit 5, a sonar unit, a launching unit 4 and a fishhook unit 3 in fishing. The method comprises manipulating the UAV to fly to a designated destination determined by the processor according to either a received wireless communication or a preset program. Then adjusting the sonar unit to a predetermined height by the positioning unit, determining a coordinate corresponding to a signal detected by the sonar unit as a fishing region when the signal is consistent with a predetermined value. Then launching bait to the fishing region by the launching unit, releasing a fishhook from the fishhook unit to the fishing region, and manipulating the UAV to hover or return by the processor according to one of a received wireless communication and a preset program. The sonar unit may be positioned by lowering it on a wire which connects the sonar unit to the positioning unit. The positioning unit may have a sensor to detect a drop in tension in the wire and cease the lowering of the sonar unit.
