Abstract: Secure access method, apparatus and system for cloud computing are provided. The method includes: acquiring authentication information input from a client; determining a client identification of the client which is not arbitrarily changeable; if it is determined that the ordinary password corresponding to the user name is correct, determining by a distribution authentication server whether a correspondence between the client identification and the address of the cloud machine exists in a database of the distribution authentication server and whether the dynamic password is correct, and notifying the client of a successful login if the correspondence exists in the database and the dynamic password is correct, and notifying the client of an unsuccessful login if it is determined that the ordinary password corresponding to the user name is incorrect.