In this paper a new method of evaluating the efficiency of non-randomized artificial precipitation enhancement-Cluster-Analysis-based Floating Control historical regression Method(CA-FCM) is presented,and compared with the traditional Floating Control historical regression Method(FCM) which does not base on cluster analysis.It is shown from six examples of effect evaluations for cloud seeding operation cases carried out in the central region of Henan Province,that the CA-FCM can more effectively evaluate the efficiency of cloud seeding operations than the FCM,because the CA-FCM adopts cluster analysis which highly improves the correlativity between rainfall distributions in the control area and target area,and chooses the atmospheric precipitable water as a covariant,thus improving the inferential accuracy of natural rainfall in the cloud seeding operation area.