我们从麦克斯韦方程和线性化矩方程出发,获得了具有电子密度梯度的弱非均匀可压缩等离子体在外场作用下的电磁波和电声波激发的耦合方程,并求得了微扰解。最后讨论了非均匀可压缩等离子体中电磁波和电声波耦合激发机制,指出不同模间耦合是产生不同模间相互转换的原因,而Cohen等人的均匀可压缩等离子体中电磁波和电声波激发过程均可视为本文的特殊情况。 Based on the Maxwell's equations and the linearized moment equations, we obtain the coupled equations of electromagnetic wave and electroacoustic wave excited by weak inhomogeneous compressible plasmas with electron density gradient in the presence of external field, and obtain the perturbation solution. Finally, the coupling excitation mechanism of electromagnetic wave and electroacoustic wave in non-uniform compressible plasmas is discussed. It is pointed out that the coupling between different modes is the reason for the mutual conversion between different modes. Cohen et al.'s electromagnetic wave and electroacoustic wave in homogeneous compressible plasma Excitation process can be regarded as a special case of this article.