通过数值模拟的方法，研究了高阶空间电荷场对匹配高斯光束在光伏光折变晶体中自偏转特性的影响。结果表明，对于给定的与晶体参量匹配的高斯光束， 高阶空间电荷场对其自偏转特性的影响与外电场和光伏场的极性和强度，以及入射光束的强度有关。当外电场、光伏场、入射光束的强度取不同的参数组合时， 就可以控制高斯光束的偏转程度，在三者特定的参数组合下，还可以实现高斯光束偏转方向的改变，进而实现高斯光束的无偏转稳定传播。

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.