Influence of higher-order space-charge field on the self-deflection of a Gaussian beam is numerically investigated. The results indicate that, for a given photovoltaic-photorefractive crystal and a Gaussian beam which matches with its parameters, the effects of the higher-order space-charge field on self-deflection of Gaussian beam depend on the polarity and strength of the two field, extra electric field and photovoltaic field, and the incident optical intensity. When the extra electric field and photovoltaic field and incident optical intensity have different combination, the self-deflection can be controlled. At an especially combination, the change of deflection direction of Gaussian beam, and even stable transmit of Gaussian beam without deflection can be realized.