本文用有限长多层介质圆柱模拟实际的树干。通过迭代方法求得无限长介质圆柱的散射场系数 ,在电大尺寸下 ,用无限长介质圆柱的内场代替有限长介质圆柱内场 ,根据等效原理 ,在远场近似下 ,由其等效表面电流源和磁流源求得有限长介质圆柱的散射矩阵。在考虑地面有一定倾角的情况下 ,分析了树干表层介电参数以及由于倾斜的地面对其散射特性的影响 ,并发现了文献〔1〕中没有给出的新现象 In this paper, a finite length multilayer cylinder is used to simulate the actual trunk. The iteration method is used to obtain the scattering field coefficient of an infinitely long dielectric cylinder. In the case of electric large size, the inner field of an infinitely long dielectric cylinder is used to replace the inner field of a finite length dielectric cylinder. According to the equivalent principle, in the far field approximation, Surface current source and magnetic current source to obtain a finite length dielectric cylinder scattering matrix. Considering the inclination of the ground, the dielectric parameters of the trunk surface and its influence on the scattering properties due to inclined ground surface are analyzed, and a new phenomenon not found in [1] is found out