A leader-follower consensus of a fractional-order multi-agent system with external disturbances is addressed throughout this paper. To suppress disturbance, we established a predictive extended state observer and designed an event-triggered control. Utilizing the Lyapunov method along with stability theory for fractional-order systems, we constructed a sufficient condition to attain a leader-follower consensus. Furthermore, we demonstrated that Zeno behavior does not appear during the triggering process. Last, we performed some numerical simulations to confirm the effectiveness of the control strategy.