The invention discloses an anti-crash device of a single-propeller unmanned aerial vehicle, comprising an unmanned aerial vehicle, an airbag, a parachute, a nylon net, a controller and an acceleration sensor, wherein the unmanned aerial vehicle is a single-propeller unmanned aerial vehicle; a parachute bag is mounted at the tail of the unmanned aerial vehicle; the parachute and an ejection device are mounted in the parachute bag, and the parachute is connected with the ejection device; the airbag is mounted at the lower part of the nose of the unmanned aerial vehicle, and the airbag is connected with a gas generator; the nylon net is arranged at the top of the unmanned aerial vehicle, and the nylon net is connected with a launcher; the ejection device, the gas generator and the launcher are respectively connected with the controller, and the acceleration sensor is connected with the controller; the controller is a single chip microcomputer; and the nylon net is arranged below the propeller of the unmanned aerial vehicle. Generally, the anti-crash device disclosed by the invention has an effect of effectively preventing the unmanned aerial vehicle from crashing.