The invention discloses a login method without password based on third party authentication, a device and a system thereof. The system comprises a client, an application system, and a third-party authentication server. The client sends a login confirmation message to the third-party authentication server. The third-party authentication server, after receiving a login request of user login application system sent by the client or the application system and the login confirmation message, executes the security authentication for users according to the user number that the login request carries and the user key that the login confirmation message carries, and executes the security authentication for the application system according to the system number that the login request carries and the application system key. After the safety authentications for the user and application system are passed, the third-party authentication server sends a login confirmation order. The application system confirms the user corresponded to the user number and calls the login process to complete the user login after receiving the login confirmation order. By the login method without password based on third party authentication, the device and the system thereof, users login to any system without entering password and verification code.