The invention discloses a cloud computing secure access method, a device and a system. The method includes obtaining authentication information input by a client, determining a client identification of the client, which can not be changed voluntarily, when a common password corresponding to a user name is determined to be correct, determining whether a corresponding relationship between the client identification and the address of a cloud machine exists in a data base of a distribution authentication server or not through the distribution authentication server, determining whether a dynamic password is correct or not as well, if the corresponding relationship exists and the dynamic password is correct, informing the client of a successful logging, otherwise, informing the client of a failed logging, and when the password information corresponding to the user name is determined to be incorrect, informing the client of a failed logging. By means of the scheme, even though an illegal user steals the user name and the common password, the illegal user is incapable of establishing the corresponding relationship between the client identification and the address of the cloud machine, and the illegal user can not obtain a permission of logging in the cloud machine through stealing the common password, and thereby the safety of logging in the cloud machine is improved.