The invention discloses a cloud auditing method with lightweight user dynamic revocation and data dynamic update. First of all, a user can implement efficient dynamic revocation (including replacementof public and private keys), and in a user revocation stage, multiple one-way proxy re-signature technologies are adopted, and a new user only needs to compute a re-signature key and does not need todownload a data re-signature from a cloud end and then upload to the cloud end; then, the data can be guaranteed to be updated (inserted, deleted and modified) dynamically in real time, and by introducing a virtual index to identity recognition codes of data blocks, when the data are updated dynamically, only the identity recognition codes of the updated data blocks change and the identity recognition codes of the rest data blocks remain unchanged; and at last, in a re-signature stage, a cloud server performs re-signature instead of a new appointed user, and in an auditing stage, a third party auditing center performs verification on integrity of the data stored at the cloud end instead of a current user; the computation overhead of a terminal user and the communication overhead of a system are greatly relieved; and the cloud auditing method is efficient and secure.