A method and a device for information system access authentication are disclosed. The method includes: performing anonymous authentication to a random verification code generated according to a login request for accessing an information system of a client, and authenticating acquired user name and password information when the anonymous authentication is successful. The device includes an verification code authentication module and a user name and password authentication module connected to the verification code authentication module, wherein the verification code authentication module is configured to perform anonymous authentication to a random verification code generated according to a login request for accessing an information system of client; and the user name and password authentication module is configured to authenticate acquired user name and password information when the anonymous authentication is successful. The present disclosure uses a two-stage and two-factor authentication method such that the security of the login information is improved without increasing the complexity of the user's login.