minimum support tree;  relationship matrix;  Network diagram

Aiming at the complex network diagram represented by the relationship matrix, the characteristics of the elements constituting the minimum support tree are analyzed, and two methods for finding the minimum support tree are proposed: direct generation method and table operation method. The two methods do not need to make complex network diagrams, but directly generate the minimum support tree from the relationship matrix, which can effectively overcome the inconvenience of traditional methods to draw network diagrams. Through case studies, the two methods have unique features in solving the minimum support tree for complex problems.