The impact of an applied field on the propagation of a Gauss beam in the photovotaic-photorefractive crystal is investigated. It indicates that, in a photovotaic-photorefractive crystal with a proper applied field, a Gauss beam can evolve into steady-state bright screening-photovoltaic optical soliton. If the applied field is not proper, the Gauss beam will experience cycles of compression and expansion. The intensity and polarity of the applied field have a remarkable influence on the wave shape of steady state bright screening-photovoltaic optical soliton. However, the polarity has a larger influence on it as compared with the intensity of the applied field.