A security check method for performing a security check between a terminal and a server, the method performed by the terminal, the method comprising: replacing an original check mode with an updated check mode for performing security checks between the terminal and the server, when performing a security check of a terminal user, by: acquiring (301; 401) first original check credential information of the original check mode, generating (302; 402) substitutive credential information for the updated check mode and storing the substantive credential information at the terminal, and transmitting (304; 404) the first original check credential information, the substitutive credential information, and user information of the terminal user from the terminal to the server for correlation of the substitutive credential information with the user information; and subsequently performing a security check between the terminal and the server using the updated check mode by: performing a local check of the terminal user at the terminal via the updated check mode to acquire a local check result, encrypting the local check result according to the substitutive credential information stored at the terminal to acquire an encrypted check result, and sending the encrypted check result, the local check result, and user information of the terminal user from the terminal to the server for verification, wherein the local check result is trustable when the encrypted check result is verifiable according to substitutive credential information corresponding to the user information. replacing an original check mode with an updated check mode for performing security checks between the terminal and the server, when performing a security check of a terminal user, by: acquiring (301; 401) first original check credential information of the original check mode, generating (302; 402) substitutive credential information for the updated check mode and storing the substantive credential information at the terminal, and transmitting (304; 404) the first original check credential information, the substitutive credential information, and user information of the terminal user from the terminal to the server for correlation of the substitutive credential information with the user information; and acquiring (301; 401) first original check credential information of the original check mode, generating (302; 402) substitutive credential information for the updated check mode and storing the substantive credential information at the terminal, and transmitting (304; 404) the first original check credential information, the substitutive credential information, and user information of the terminal user from the terminal to the server for correlation of the substitutive credential information with the user information; and subsequently performing a security check between the terminal and the server using the updated check mode by: performing a local check of the terminal user at the terminal via the updated check mode to acquire a local check result, encrypting the local check result according to the substitutive credential information stored at the terminal to acquire an encrypted check result, and sending the encrypted check result, the local check result, and user information of the terminal user from the terminal to the server for verification, wherein the local check result is trustable when the encrypted check result is verifiable according to substitutive credential information corresponding to the user information. performing a local check of the terminal user at the terminal via the updated check mode to acquire a local check result, encrypting the local check result according to the substitutive credential information stored at the terminal to acquire an encrypted check result, and sending the encrypted check result, the local check result, and user information of the terminal user from the terminal to the server for verification, wherein the local check result is trustable when the encrypted check result is verifiable according to substitutive credential information corresponding to the user information.