Abstract: To address the issue of state information uncertainty in multi-agent systems under denial-of-service (DoS) attacks, we propose a state observer. Based on this observer, wen design an event-triggered protocol to separate the leader-follower errors from the inter-follower errors. This protocol aims to optimize the communication and coordination mechanism among agents, enable each agent to be triggered individually, and reduce the update frequency of controllers. Subsequently, we analyze the stability of the error system using Lyapunov functions and induction methods, with sufficient conditions for achieving follower control being derived. Furthermore, we theoretically guarantee the proposed triggering mechanism to preclude Zeno behavior through rigorous proof of a strictly positive minimum inter-event time. Finally, numerical simulations validate the effectiveness and robustness of the proposed control strategy.