The invention discloses an unmanned aerial vehicle system and a method for dynamically positioning a ground moving target, belonging to the fields of unmanned aerial vehicle system application and the like. The unmanned aerial vehicle system comprises an unmanned aerial vehicle body, a vehicle-mounted photoelectric rotating tower and a ground control terminal, wherein the unmanned aerial vehicle body comprises an acquisition device, the vehicle-mounted photoelectric rotating tower comprises a photoelectric sensor and a sight-stabilizing platform, and the ground control terminal comprises a determining device, a trace command generating device, a resolving device and a predicting device. According to the technical scheme provided by the invention, geographical coordinate information including latitude, longitude and the like of a tracked ground moving target can be output in real time, the original geographical coordinate information can be accurately and quickly fitted, the moving trend of the ground moving target can be predicted and evaluated, and the original geographical coordinate information can be screened to realize display and prediction of the track of the moving target; the positioning accuracy acquired by the unmanned aerial vehicle system and the method approaches that of static positioning and can meet requirements for initial alignment of weapons including artilleries and the like, and the probability of fusion processing of an unmanned aerial vehicle intelligence system and an entire-army intelligence gathering network is provided.