Abstract: The formation method of connected-dominating set (CDS) in ad hoc wireless network is studied and improved. There are two improvements in this paper, the first one is numbering the nodes by introducing the eigenvector center value of the network topology information, which avoids the randomness during node reduction and makes the node reduction be related to the actual network topology closely. The second one is that CDS algorithm ignores the removal of the largest numbered nodes, the improved one proposes a new rule to achieve the reduction of the maximum number nodes. Thus, the improved method solves the NP-complete problem of the CDS algorithm in formation method of connected-dominating set and achieves the conditional optimal connected-dominating set. The simulation results show the excellent characteristics of the improved method.