Abstract: Dealing with the problem of lacking high availability in trust services under hosting cloud computing environment, an time effectiveness strategy and an time effectiveness model for hosting cloud computing were proposed from the perspective of service evaluation in trust. It dynamically calculate trustworthiness degree of hosting cloud service node by utilizing threshold methods, IOWA (induce ordered weighted averaging) operators, transparent trust evaluation and dynamic level scheduling algorithm. Our experimental results showed that this hosting cloud time effectiveness strategy can choose high credibility service resources in priority, and enhanced the stability and availability of cloud services application to some extent.