The invention discloses a robot cleaner realizing posture-changing flying. The robot cleaner comprises a ducted posture-changing flying device, a moving device and a cleaning device, wherein a motor drives a ducted fan to rotate so that the air inside a shell of the robot cleaner is pumped out, meanwhile, through the deflection of guide vanes, the movements including pitching, horizontal rolling, yawing and the like of the robot are controlled, so that the robot can realize vertical flying, horizontal flying and hovering, and then the face-face converting capacity is achieved. For the robot cleaner realizing posture-changing flying, through the conversion among different wall surfaces, the dust on the wall and the ceiling can be cleaned and brushed, and in addition, the robot cleaner can stably hover on the wall and flexibly move and turn on the wall, so as to adapt to different work environments and demands.