为了解决三维目标电磁散射计算中准确性与有效性的矛盾，建立了有限元-边界法的计算模型，对三维腔体目标的电磁散射计算方法进行了研究。首先，分析了针对三维电磁腔体目标的电磁散射计算边界积分方法，引入了矢量格林函数，利用麦克斯韦方程得到电磁场形式与三维腔体形式的关系，建立了三维开口腔体边界模型; 然后，结合光电目标曲面建模方法及高阶基函数的方法，建立了三维光电目标的有限元泛函，完成了有限元-边界法在三维腔体目标电磁散射计算中的应用; 最后，进行了实例验证。分析显示，当三维腔体内部为空或为各向异性物质时，角度吻合非常理想，与传统模式匹配法所得结果的吻合度达90%以上。结果表明，采用本方法对三维腔体目标进行电磁散射计算，准确度、效率均有所提高。

In order to solve the contradiction between veracity and validity for calculating the three-dimensional target electromagnetic scattering, a calculator mode about Finite Element-Boundary Integral(FE-BI) was set up to calculate the three-dimensional target electromagnetic scattering. Firstly, the three-dimensional target electromagnetic scattering calculation borderline integral was analyzed, and the vector Green function was introduced. On the basis of the connection between electromagnetism form and three-dimensional cavity form, the three-dimensional hatch cavity borderline mode was set up. Then, the finite element commonly function was established by combining the optical target surface modeling method with the higher order function method, and the application of the FE-BI to calculating three-dimensional target electromagnetic scattering was achieved. Finally, the following example analysis was proved. It is shown that the angle tally is very ideal when the dimensional bosom is empty or anisotropic matter. The consistance has been 90% as compared with the traditional matching method. In conclusion, the veracity and validity of calculation are improved by the proposed method.