Abstract: In order to solve the problem of complicated steps and large communication volume caused by the participation of trusted or semi-trusted third parties in the existing mutual authentication quantum key agreement protocols, a new two-party quantum key agreement protocol is proposed based on Bell states and their entangled exchange properties. The key agreement protocol can realize identity mutual authentication and fair key agreement between participants without the participation of trusted or semi-trusted third parties, thus reducing the communication complexity of the protocol. The security analysis shows that its identity authentication process can resist impersonation attack, and its key agreement process can resist external attacks and participant attacks. In addition, compared with the existing mutual authentication quantum key agreement protocols, the quantum bit efficiency of the protocol is also higher, and its quantum state preparation and measurement are easier to achieve with existing technologies.