外推近似方法在原子核壳模型上取得了一些成功,然而人们对于其原理知道得比较少。这里主要研究并讨论了随机两体系综和高斯正交系综最小本征值。利用截断空间的外推解释了高斯正交系综下的外推公式以及随机两体系综下本征值外推收敛的鲁棒性,即对于壳模型有效相互作用而言,用外推法预言最低本征值收敛性很好。 Extrapolation approximations have achieved some success in the kernel shell model, yet people know less about their principles. Here we mainly study and discuss the minimum eigenvalue of random two-system ensemble and Gaussian orthogonal ensemble. The extrapolation formula of Gaussian orthogonal system and the robustness of extrapolation and convergence of the eigenvalues ​​under the random two-system synthesis are explained by the extrapolation of the truncation space. That is to say, for the effective interaction of the shell model, extrapolation is used to predict The minimum eigenvalue convergence is good.