Uncertainty analysis is one of the hot research issues in the field of computational electromagnetics in the past five years. The Method of Moments is a non-embedded uncertainty analysis method with relatively high computational efficiency and has the unique advantage of not being affected by the "curse of dimensionality". However, when the nonlinearity between the simulation input and output is large, the accuracy of the Method of Moments is not ideal, which severely limits its application in the field of computational electromagnetics. In this paper, an improved strategy based on the central clustering algorithm is proposed to improve the expected value prediction results of the Method of Moments, thereby improving the accuracy of the overall uncertainty analysis. At the same time, the co-simulation technology of MATLAB software and COMSOL software is completed, then the accuracy and computational efficiency of the proposed algorithm in this paper are quantitatively verified. In this case, the clustering Method of Moments is effectively popularized in commercial electromagnetic simulation software.