The invention relates to an arm folding assembly and an unmanned aerial vehicle, which relates to the technical field of the unmanned aerial vehicle. The arm folding assembly comprises a connecting member, a fixing sleeve, an arm receiving cylinder and a limit stopper. The connector comprises a connector body, two flanges extend to the same side at one end of the connector body and are arranged inparallel, and a plurality of anti-slip projections are arranged at the other end of the two flanges away from the connector body. The connector body is movably connected to the outer wall surface ofthe fixing sleeve. One end of the arm receiving cylinder is fixedly sleeved in the fixing sleeve. The limiting stopper comprises a bottom plate and two side plates extending upward from two sides of the bottom plate, and the other end of the arm receiving cylinder is movably connected between the two sides plates, one side of the two sides plates facing the arm receiving cylinder is formed with afirst notch, and one side of the two sides plates opposite to the first notch is formed with a second notch. The arm folding assembly solves the problem that the unmanned aerial vehicle occupies largespace and is inconvenient to store in the prior art.