The trusted virtual platform constructed by the combination of virtualization technology and trusted computing and its trust chain have become a research hot spot. But at present, most of the research achievements construct the trust chain by extending the conventional trust chain model, as a result, the model is not precise and the logic is not completely reasonable. Moreover, there are two separate trust chains, one starts from the underlying virtual platform, the other starts from the top-level user Virtual Machine (VM). In order to solve this problem, a trust chain model with waterfall characteristic called TVP-QT was proposed for the trusted virtual platform. This model starts with the physical Trusted Platform Module (TPM), and adds a Trusted-Joint Point (TJP) between the chain of the underlying virtual platform and the chain of the top-level user VM. The TJP is in charge of the measurement of virtualization TPM (vTPM) for VM after the trusted chain is transmitted from the underlying virtual platform to the TJP, then the vTPM gets the control and is in charge of the measurement of the related components and applications of the top-level user VM in the starting process. The TJP which has the waterfall characteristic between the underlying virtual platform and the top-level user VM can be viewed as a connecting link, and it can satisfy the hierarchical and dynamic characteristics of the virtual platform, moreover guarantee the trust of the whole virtual platform. Finally, the correctness of the model was proved in theory, and the generality and feasibility of the proposed trust chain model in the instantiation system was analyzed and discussed. Simulation results on Xen show that the trust chain can ensure the trust and credibility of the trusted cloud platform in the whole running process.