<p>In three-party communication scenarios, ensuring data security and integrity during transmission while addressing the issue that ordinary users cannot afford expensive quantum devices remains a critical challenge. To tackle this problem, this paper proposes a semi-quantum key agreement protocol based on GHZ-like states and chaotic sequences, wherein key agreement is only executed after the completion of identity authentication. The core innovation of this scheme lies in the implementation of mutual authentication among the three parties: the quantum server performs explicit authentication on the participants, while the participants themselves conduct implicit authentication for information transmission. Specifically, authentication can be achieved by comparing the information sent by the quantum server with that transmitted by another participant, which significantly enhances the security of interactive processes. Furthermore, chaotic sequences are incorporated into the key generation phase, which not only improves the security of the shared key but also reduces the consumption of quantum resources. Security analysis demonstrates that the proposed protocol can effectively resist typical attacks, including reflection attacks, intercept-resend attacks, and impersonation attacks. Finally, a comparative analysis of efficiency with other existing schemes is conducted, and the results show that the communication efficiency of the proposed protocol reaches up to 16.7%.</p>