The invention provides an authentication method and system for mobile subscribers, which can realize the password-free registration and login and have advantages of convenience in use, high safety and low cost. The authentication method for the mobile subscribers of a third-party application of an Andriod system or an iOS system comprises the following steps: completing access registration of a third-party application on a safety service platform apparatus; and registering a safety service card application apparatus so as to establish a user information database; and when a user logs in at a first time, transmitting, by the safety service platform proxy apparatus SDK, a mobile phone number of a user to the safety service platform apparatus to perform the authentication, if the mobile phone number of the user passes the authentication, generating, by the safety service platform apparatus, an exclusive OpenID, and returning, by the safety service platform apparatus, a user authentication result and the OpenID to the third-party application by virtue of the SDK; and when the user logs in at a second time, transmitting, by the SDK, the OpenID to the safety service platform apparatus to perform the authentication, and if the OpenId passes the authentication, returning, by the safety service platform apparatus, the user authentication result and the user mobile phone number to the third-party application by virtue of the SDK.