A wind power generating device installed in a vehicle, characterized in that the wind power generating device comprising: a fan blade being rotated when receiving a wind force; a rotating device including a rotating disk, a plurality of magnetic elements, a plurality of ball chambers and a plurality of balls, the rotating disk having a shaft connecting portion, the shaft connecting portion being coaxial with the rotating disk, the rotating disk kinetically connected to the fan blade through the shaft connecting portion to enable the rotating disk to rotate with the fan blade coaxially, the plurality of magnetic elements being annularly arranged at a periphery area of the rotating disk respectively, each magnetic element being allocated in a magnetic moment direction that shifts with a deviating angle (θ1) from a radial direction of the rotating disk, the plurality of ball chambers being annularly arranged by surrounding the shaft connecting portion, each ball chamber extending outward from an outer wall of the shaft connecting portion, each ball chamber being formed with two side walls, each side wall being allocated as being shifted with a wall shifting angle (θ2) from the radial direction of the rotating disk, and each ball chamber being provided with at least one ball; a securing ring neighbored and surrounding the rotating disk, the securing ring including a plurality of corresponding magnetic elements, each corresponding magnetic element being configured as annularly arranging in inner peripheral of the securing ring and facing the rotating disk in such a manner that the corresponding magnetic element is with magnetic repulsion to the magnetic element such that a magnetic repelling force between the magnetic elements and the corresponding magnetic elements is generated; and a power generating device having a power input shaft, the power input shaft being kinetically connected to the shaft connecting portion so as to rotate with the rotating disk. a fan blade being rotated when receiving a wind force; a rotating device including a rotating disk, a plurality of magnetic elements, a plurality of ball chambers and a plurality of balls, the rotating disk having a shaft connecting portion, the shaft connecting portion being coaxial with the rotating disk, the rotating disk kinetically connected to the fan blade through the shaft connecting portion to enable the rotating disk to rotate with the fan blade coaxially, the plurality of magnetic elements being annularly arranged at a periphery area of the rotating disk respectively, each magnetic element being allocated in a magnetic moment direction that shifts with a deviating angle (θ1) from a radial direction of the rotating disk, the plurality of ball chambers being annularly arranged by surrounding the shaft connecting portion, each ball chamber extending outward from an outer wall of the shaft connecting portion, each ball chamber being formed with two side walls, each side wall being allocated as being shifted with a wall shifting angle (θ2) from the radial direction of the rotating disk, and each ball chamber being provided with at least one ball; a securing ring neighbored and surrounding the rotating disk, the securing ring including a plurality of corresponding magnetic elements, each corresponding magnetic element being configured as annularly arranging in inner peripheral of the securing ring and facing the rotating disk in such a manner that the corresponding magnetic element is with magnetic repulsion to the magnetic element such that a magnetic repelling force between the magnetic elements and the corresponding magnetic elements is generated; and a power generating device having a power input shaft, the power input shaft being kinetically connected to the shaft connecting portion so as to rotate with the rotating disk.