The biometric technologies for user authentication have been applied widely to identity authentication fields. But at present, the result of research on a biometric authentication system which is used for open networks has not been found. Identity authentication based on X.509 Public Key Infrastructure(PKI) and Privileges Management Infrastructure(PMI) are used widely and effectively in open network fields for authentication and privileges management. So on the basement of PKI and PMI technology, with the function of identity authentication and privileges management, the currency biometric identity authentication system based on Biometric Certificate is introduced. Finally, by designing a highly secure biometric smart card which can realize identity authentication and privileges management, proved the ability and operation of the currency biometric identity authentication system based on PKI and PMI technology.