Self-deflection characteristics of screening bright soliton in photorefractive crystal applied alternating electric field were discussed by perturbation method. This soliton is formed in the crystal when the direction of effective electric field of alternating electric field is along with crystal axis, while the self-deflection of the soliton orients the direction opposite crystal axis. Moreover, the deflection distance of the soliton center moving along a parabolic trajectory is proportional to the modulation degree of light intensity and third power of alternating electric field, respectively. It is worth to mention that this distance reaches maximum value for the ratio of center light intensity of soliton to the dark radiation intensity up to 10. Besides, the spatial frequencies of soliton center, along with self-deflection, transfer from the lower components of the spectrum into the higher components linearly, resulting in change for amplitude distribution of soliton in which the slope of the curve gets larger in deflection direction and smaller for the opposite.