<p>This paper investigates the anti-attack fuzzy tracking control mechanisms for high-order nonlinear multi-agent systems (MASs) subject to multi-channel independent denial-of-service (DoS) attacks and actuator failures. Initially, a novel observer based on topology switching is proposed, utilizing topology switching induced by DoS attacks as trigger conditions. This observer incorporates an “active delay” to ensure effective estimation of the leader’s state information within the joint connectivity topology graph. Furthermore, an algorithm that relies on topological connectivity to determine the triggering instants is developed. To address the issue of non-existence of high-order derivatives in the designed observer, an improved observer incorporating high-order derivatives is proposed. Additionally, through the integration of fuzzy logic systems (FLSs) and the backstepping method, a fuzzy secure tracking controller is designed for each agent. To alleviate the transmission pressure, input quantization is employed to transform the continuous control signals into discrete, finite sets. The proposed control scheme mitigates the limitation of DoS attack and the trigger frequency of the observer, and achieves the tracking control of MASs. Finally, by means of simulation examples, the safety and validity of the method are illustrated.</p>