Purpose <p>This paper investigates the dynamic response characteristics of a fixed-point rubbing fault in magnetic suspension dual-rotor systems (MSDS) under interference fit uncertainty. The main research question is how the uncertainty in the interference fit affects the system’s vibration and dynamic response.</p> Methods <p>To accurately assess the uncertainty in the interference fit, an interval method is introduced to quantify this parameter. An uncertainty dynamic model of the MSDS with a fixed-point rubbing fault is established using the interval method. The applicability of the model is discussed and validated through analysis.</p> Results <p>The study explores the effects of system speed, initial interference fit, and its uncertainty on rotor vibration amplitude and rubbing characteristics. The results demonstrate that the interval method effectively captures the rubbing characteristics under uncertainty. Additionally, system speed, interference fit, and its uncertainty are shown to have a significant impact on rotor vibration and rubbing behavior during operation.</p> Conclusion <p>The findings provide new theoretical guidance for the design and optimization of magnetic levitation rotor systems. They hold important practical value by enhancing system reliability and reducing the risk of rubbing faults.</p>