Unmanned aerial vehicle and retainer assembly thereof

The guard ring assembly is arranged on a paddle assembly in a foldable mode, the guard ring assembly comprises a first half ring and a second half ring, the second half ring is rotatably connected to the first half ring through a connecting structure, and the connecting structure comprises a rotating section, a rotation stopping section and a rotation stopping hole formed in the second half ring; the rotation stopping hole is matched with the rotation stopping section in shape. When the rotation stopping section is located in the rotation stopping hole, relative rotation of the second semi-ring and the first semi-ring can be limited, and when the rotating section is located in the rotation stopping hole, the second semi-ring and the first semi-ring rotate relative to each other, so that the second semi-ring and the first semi-ring are switched between a folded state and an unfolded state. The protective ring assembly can provide comprehensive protection for the propeller, the risk that a user stretches finger