The invention belongs to the technical field of pavement flatness measuring devices, and discloses an unmanned aerial vehicle aerial platform-based pavement flatness measuring device, which comprises an unmanned aerial vehicle main body, supporting legs and a mounting top plate are fixedly mounted at the bottom end of the unmanned aerial vehicle main body, and a placement box is mounted at the bottom end of the mounting top plate through a connecting
assembly. A
measuring instrument is arranged in the placement box, a buffer
assembly is arranged in the unmanned aerial vehicle main body, a protection
assembly is arranged in the placement box, the buffer assembly comprises a parachute arranged in the unmanned aerial vehicle main body, a stall sensor is mounted in the mounting top plate, an
air pump is arranged in the placement box, and the side wall of the
air pump is connected with an air inlet
pipe. When the unmanned aerial vehicle body falls, the stall sensor monitors that the landing speed of the unmanned aerial vehicle body is changed, the parachute is controlled to be opened to slow down and slowly descend, the
air pump is started, the air inlet
pipe is made to spray air, counter-acting force is provided, the falling posture and stability of the unmanned aerial vehicle body are adjusted, and the safety of the measuring device is improved.