The invention discloses an air deflector, an air conditioner and a control method and device of the air conditioner. A rotating part is arranged at one end, in the width direction, of the air deflector, a first connecting part and a second connecting part are arranged at the two ends, in the length direction, of the rotating part correspondingly, the first connecting part is arranged to be connected with the driving mechanism, and the second connecting part is arranged to be rotatably connected with the supporting carrier; the rotating part is further provided with at least one third connecting part, the third connecting part is located between the first connecting part and the second connecting part, and the third connecting part is arranged to be rotatably connected with the supporting carrier so as to limit the air deflector to be separated from the supporting carrier. According to the scheme, the rotating part of the air deflector is transferred to one end of the width direction of the air deflector, and at least one third connecting part is additionally arranged, so that multi-point supporting connection of the air deflector and the supporting carrier is realized, and the situation that the rotating part of the air deflector deviates from a set rotating axis and is separated from the supporting carrier due to bending, deformation, interference and the like of the air deflector is prevented; and therefore, the use reliability of the air deflector is improved.