Abstract: In the cloud data center,virtual machine consolidation (VMC) is one of the key technologies for green computing and minimizing cluster power consumption.In the relevant research works,most seek the most reasonable consolidation schemes based on resource utilization and don't consider the stability and availability of PM and co-located virtual machines (VM).In this paper,by analyzing their mutual exclusion conditions,a virtual machine consolidation strategy is proposed,in which both the availability of PM and the mutual exclusivity among VM are considered.Moreover,the cluster server uniform resources reservation approach and the similarity calculation method based on the historical running data of VM are also given.Finally,this strategy is evaluated by collecting and analyzing the running data of VM deployed on the open stack platform.Experiment results show that the proposed method can effectively guarantee the PM availability and avoid the situation that the same type of VM is consolidated in one PM.Hence,this algorithm can reduce the performance degradation of co-located VM and improve the quality of service (Qos).