Abstract: A collision avoidance formation control strategy for fixed-wing UAV fleet based on extended state observers is proposed. In the presence of external disturbances in the formation system, such as gusts, the extended state observers are designed to estimate these disturbances. The convergence of the estimated error indicators to a small neighborhood around the origin point is proven. To address the challenges of input saturation and communication delays inherent in UAV system control, a collision-free saturated control strategy is presented with potential function and anti-saturation compensator approaches. Furthermore, the control algorithm takes into account the impact of time-varying communication delays. It is demonstrated that the closed-loop system exhibits asymptotic stability. Finally, the proposed control approaches are verified by numerical simulation examples.