The invention discloses a deflection mechanism of a fan blade hoister for a wind driven generator. The deflection mechanism of the fan blade hoister for the wind driven generator is used for assisting in adjusting the gesture of fan blades during fan blade mounting and dismounting through the fan blade hoister in an aloft unsupervised state and is simple in whole structure, convenient to use and high in automation degree, and manual interference is not needed. Compared with existing deflection mechanisms, the phenomenon that the deflection mechanism gets stuck due to inclination of gravity centers of hoisted objects is not liable to occur. The deflection mechanism comprises tracks, a movable trolley, a lead screw, a motor, a speed reducer and a nut. The transversely arranged lead screw is sleeved with the nut. The lead screw penetrates through the movable trolley and is fixedly connected with the movable trolley through the nut. Rolling wheels are arranged at the bottom of the movable trolley and are placed on the tracks. The tracks and the lead screw are in parallel in the axial direction. The output end of the motor is connected with the speed reducer. The lead screw penetrates through a hole in an output shaft of the speed reducer and form a 90-degree included angle with the output shaft of the speed reducer. The speed reducer drives the lead screw to rotate, and the movable trolley does linear movement along the tracks.