Markov network is a forceful tool to practice inference of uncertainty.It is an undirected graph,and it doesn’t need to find the direction of an edge.On the basis of testing information independence theory,the test of CI is carried out on all the nodes in the Markov network.Meanwhile,an effective structural algorithm based on information entropy is pre-sented in this paper,it greatly improves the reasoning efficiency,and has the reference value for uncertain reasoning re-search of knowledge.