The invention discloses an information flow dependability guarantee mechanism for cloud computation. The information flow dependability guarantee mechanism for cloud computation comprises the process that information is transmitted, the process that the information is processed by an in-cloud service and the process that the information is stored in a cloud platform. In the process that the information is transmitted, a transmission and conversion agent is built between the cloud and a user and used for mixing and converting confidential and private data in information flow sent to the cloud platform. In the process that the information is processed by the in-cloud service, an information processing and verification agent is built on the cloud to guarantee that execution of the information flow between undependable services or within the services complies with a specified dependability strategy. In the process that the information is stored in the cloud platform, a storage control agent is designed on a programming platform, data obtained after mixing and conversion are stored and monitored, so that dependability of data storage is guaranteed. The information flow dependability guarantee mechanism provides theoretical verification and technical support for wide application of cloud computation.