The invention discloses a folding rotor-type unmanned aerial vehicle. The folding rotor-type unmanned aerial vehicle can be folded compactly and unfolded quickly, so that the application flexibility of the rotor-type unmanned aerial vehicle is enhanced effectively. The unmanned aerial vehicle comprises a main body, four rotor arms and a
landing gear, wherein each rotor arm is folded and unfolded reliably through a hinge mechanism and a limiting and
locking mechanism. When the unmanned aerial vehicle is in a folded state, the rotor arms are positioned in axial grooves in the main body, a
torsion spring in the hinge mechanism is compacted, and a limiting and locking piece is positioned at a locked position under the action of a reset spring. When the rotor arms of the unmanned aerial vehicle are required to be unfolded, the limiting and locking piece is driven to slide through a stirring piece along the circumferential direction of the main body, so that the rotor arms are unlocked; the rotor arms are driven to fall quickly by the
torsion spring under the effect of torsional force and are limited in a horizontal state. After the rotor arms are unfolded completely, the stirring piece is released, and the limiting and locking piece is returned to the locked position under the effect of the reset spring, so that the rotor arms in an unfolded state are limited and locked.