Abstract: Gating beam intensity effect on the self-deflection of bright photovoltaic spatial solitons in two-photon photovoltaic photorefractive media was numerically investigated based on diffusion effect. Taking the bright photovoltaic solitons as the input solitary beam, the beam propagation equation was numerically solved in which the diffusion term was taken into account. The full width of half maximum (FWHM) of solitons intensity profile increases with gating beam intensity. The distance of self-deflection of solitons increases with gating beam intensity and starts to decrease when gating beam intensity is increased over a specific value. The nonlinear relation between self-deflection distance and gating beam intensity results from the effects of FWHM and diffusion term.