To overcome the problems that there are unsafe loopholes, functional duplication in TCG authorization protocols, a new trusted computing authorization protocol is proposed in the paper, in which the session key is introduced in the new protocol generated by Diffie_Hellman algorithm to guarantee its confidentiality. The new protocol can provide the function of anti-replay attack and can be applied to multiple entities. It can also guarantee the communication integrity and confidentiality of data effectively. The security properties are analyzed and verified by BAN logic in the paper.