Power system of unmanned aerial vehicle

The invention provides a power system of an unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicles. The problem of how to improve the flight stability of the unmanned aerial vehicle is solved. The power system of the unmanned aerial vehicle comprises an engine box, a crankshaft and a propeller shaft, the crankshaft is arranged in the front-back direction of the unmanned aerial vehicle, the rear end of the crankshaft is provided with an output section extending out of the engine box, the propeller shaft is arranged above the output section in parallel, the engine box is fixedly connected with a supporting seat, and two first bearings arranged at intervals are arranged in the supporting seat; a propeller shaft is rotationally connected into the supporting seat through a first bearing and is in transmission connection with the output section through a transmission mechanism, a starting motor fixedly connected with the engine box is arranged under the supporting seat, and a motor