The invention discloses an aerial vehicle flight error connecting device and correcting method as well as an unmanned aerial vehicle. The correcting method comprises steps as follows: an aerial vehicle height H and continuously shot ground images are acquired by an optical flow sensing module, and the optical flow sensing module performs data processing to obtain signals of aerial vehicle velocity V; an inertial navigation module performs inertial navigation on the aerial vehicle and generates corresponding inertial navigation data; a flight control unit receives the aerial vehicle velocity signals transmitted by the optical flow sensing module and the inertial navigation data transmitted by the inertial navigation module and performs data processing, and flight error correction is performed on the inertial navigation by the aid of the aerial vehicle velocity signals. According to the technical scheme, flight errors can be still corrected in the environment where GPS (global positioning system) signals cannot be received and accurate navigation for the aerial vehicle is realized.