The invention discloses a landing gear of an unmanned aircraft. The landing gear comprises a first supporting column, a second supporting column, a third supporting column, a first buffering device, a first supporting device, a second buffering device, a second supporting device and a third buffering device, wherein a first rectangular groove, a rolling wheel and a first bracket are formed / arranged in / on the first supporting column; a first groove, a second groove, a first spring, a first movable block and a rectangular block are formed / arranged in / on the second supporting column; a first positioning rod and a second spring are arranged on the third supporting column; the first buffering device comprises a first fixed rod, a first rotary rod, a second rotary rod, a first fixed block, a third spring and a positioning part; the first supporting device comprises a second bracket, a first supporting rod, a first transverse rod and a third bracket; the second buffering device comprises a first horizontal plate, a second positioning rod, a second horizontal plate, a clamping part and an elastic part. Through the adoption of the landing gear disclosed by the invention, the unmanned aircraft can be well and firmly supported; besides, the landing gear has good buffering performance, so that the unmanned aircraft can be prevented from being damaged.