A method for registering a user identity, the method comprising: receiving (S301), by a terminal device, biometric feature information of a user who is to be verified, wherein the user has a registered account with a service provided by a server; matching (S302), by the terminal device, a piece of locally stored standard biometric feature information that is consistent with the received biometric feature information of the user who is to be verified, wherein each piece of locally stored standard biometric feature information is allocated a respective biometric feature identifier and is used to determine whether a respective user can be verified when using the service; determining, by the terminal device, whether a private key corresponding to a biometric feature identifier of the piece of locally stored standard biometric feature information is stored at the terminal device, comprising searching (S303), by the terminal device and after the matching succeeds, for a private key corresponding to a biometric feature identifier of the piece of locally stored standard biometric feature information; and in response to determining that a private key corresponding to a biometric feature identifier of the piece of locally stored standard biometric feature information is not stored at the terminal device, determining that the received biometric feature information of the user who is to be verified belongs to the user but is not biometric feature information provided by the user during initial registration with the server and directly registering (S304) a user identity with the server based on the received biometric feature information of the user who is to be verified and the corresponding re-generated private key and public key, wherein the server stores the generated public key corresponding to the received biometric feature information of the user who is to be verified (S304) and the mapping relationship between the respective biometric feature identifier and the generated public key. receiving (S301), by a terminal device, biometric feature information of a user who is to be verified, wherein the user has a registered account with a service provided by a server; matching (S302), by the terminal device, a piece of locally stored standard biometric feature information that is consistent with the received biometric feature information of the user who is to be verified, wherein each piece of locally stored standard biometric feature information is allocated a respective biometric feature identifier and is used to determine whether a respective user can be verified when using the service; determining, by the terminal device, whether a private key corresponding to a biometric feature identifier of the piece of locally stored standard biometric feature information is stored at the terminal device, comprising searching (S303), by the terminal device and after the matching succeeds, for a private key corresponding to a biometric feature identifier of the piece of locally stored standard biometric feature information; and in response to determining that a private key corresponding to a biometric feature identifier of the piece of locally stored standard biometric feature information is not stored at the terminal device, determining that the received biometric feature information of the user who is to be verified belongs to the user but is not biometric feature information provided by the user during initial registration with the server and directly registering (S304) a user identity with the server based on the received biometric feature information of the user who is to be verified and the corresponding re-generated private key and public key, wherein the server stores the generated public key corresponding to the received biometric feature information of the user who is to be verified (S304) and the mapping relationship between the respective biometric feature identifier and the generated public key. <EOS>