A KYC, Know Your Client, check method on an identity of a to-be-identified user, wherein the method is applied to a privacy computing unit and comprises: obtaining a check-triggering instruction sent by an external server, comprising receiving the check-triggering instruction sent by the external server wherein the check triggering instruction is received by a first smart contract deployed in the privacy computing unit, and wherein the external server is a timing server deployed separately to trigger information verification periodically; obtaining encrypted standard basic data of the to-be-identified user from a trusted institution in response to the check-triggering instruction; decrypting the encrypted standard basic data of the to-be-identified user obtained from the trusted institution to obtain standard basic data of the to-be-identified user, wherein the standard basic data is trustworthy data; obtaining basic data of the to-be-identified user by decrypting encrypted basic data of the to-be-identified user uploaded by a first institution being a consignment agency; and performing, using the first smart contract, a consistency check on the basic data of the to-be-identified user based on the standard basic data, comprising: comparing the basic data of the to-be-identified user with the standard basic data to obtain a check result; and when the check result indicates that the basic data of the to-be-identified user is consistent with the standard basic data, determining that the basic data of the to-be-identified user uploaded by the first institution is real data; or when the check result indicates that the basic data of the to-be-identified user is inconsistent with the standard basic data, determining that the basic data of the to-be-identified user uploaded by the first institution is false data. obtaining a check-triggering instruction sent by an external server, comprising receiving the check-triggering instruction sent by the external server wherein the check triggering instruction is received by a first smart contract deployed in the privacy computing unit, and wherein the external server is a timing server deployed separately to trigger information verification periodically; obtaining encrypted standard basic data of the to-be-identified user from a trusted institution in response to the check-triggering instruction; decrypting the encrypted standard basic data of the to-be-identified user obtained from the trusted institution to obtain standard basic data of the to-be-identified user, wherein the standard basic data is trustworthy data; obtaining basic data of the to-be-identified user by decrypting encrypted basic data of the to-be-identified user uploaded by a first institution being a consignment agency; and performing, using the first smart contract, a consistency check on the basic data of the to-be-identified user based on the standard basic data, comprising: comparing the basic data of the to-be-identified user with the standard basic data to obtain a check result; and when the check result indicates that the basic data of the to-be-identified user is consistent with the standard basic data, determining that the basic data of the to-be-identified user uploaded by the first institution is real data; or when the check result indicates that the basic data of the to-be-identified user is inconsistent with the standard basic data, determining that the basic data of the to-be-identified user uploaded by the first institution is false data. comparing the basic data of the to-be-identified user with the standard basic data to obtain a check result; and when the check result indicates that the basic data of the to-be-identified user is consistent with the standard basic data, determining that the basic data of the to-be-identified user uploaded by the first institution is real data; or when the check result indicates that the basic data of the to-be-identified user is inconsistent with the standard basic data, determining that the basic data of the to-be-identified user uploaded by the first institution is false data.