A method and a system for searching for a global minimum are provided. First, a subclass of a plurality of space points in a multidimensional space is clustered into a plurality of clusters through a clustering algorithm, wherein each of the space points is corresponding to an error value in an evaluation function. Then, ellipsoids for enclosing the clusters in the multidimensional space are respectively calculated. Next, a designated space corresponding to each of the ellipsoids is respectively inputted into a recursive search algorithm to search for a local minimum among the error values corresponding to the space points within each designated space. Finally, the local minimums of all the clusters are compared to obtain the space point corresponding to the minimum local minimum.