Intet of things has been widely applied to industrial control, smart city and environmental protection, in these applica-tion scenarios, sensing node needs to make real-time response to the feedback control of the application layer. Therefore, it is nec-essary to monitor whether or not awareness nodes are trusted in real time, but the existing mechanisms for trusted certification lack the real-time measurement and tracking of the sensing node. To solve the above problems, this paper proposes a dynamic metric based authentication mechanism for sensing nodes of Intet of things. Firstly, the dynamic trustworthiness measure of the sensing nodes is carried out by introducing the computational function such as the trust function, the trust-worthiness risk assessment function, the feed-back control function and the active function of the sensing node. The dynamic trustworthi-ness measure of sensing nodes from multiple dimensions can effectively describe the change of trusted value of sensing nodes. Then, on the basis of this, a trusted attestation based on node trusted measure is realized by using the revocable group signature mechanism of local verifier. The mechanism has anonymity, un-forgeability and traceability, which is proved the security in the standard model. Simulation experiments show that the proposed trusted attestation mechanism is flexible, practical and efficient and has better attack resistance. It can effectively guarantee the reliable data transmission of nodes and realize the dynamic tracking of node reliability, which has a lower impact on system performance.