A method, a device, a terminal, and a service are described for a security check for terminal users. The method may include: performing a local check via an updated check mode to acquire a local check result, when a terminal user performs the security check; encrypting the local check result according to stored substitutive credential information to acquire an encrypted check result, wherein the substitutive credential information is generated when the updated check mode is used to replace an original check mode; and sending the encrypted check result, the local check result and user information of the terminal user to a server, so that the server determines that the local check result is trustable when the verification of the encrypted check result according to substitutive credential information corresponding to the user information is passed.