<p>High-speed aerostatic spindles have found widespread application in precision machining instruments. During the machining process, these spindles are constantly subjected to external excitations, which are crucial factors influencing spindle stability. However, current research on the specific impact of coupled external excitations on the vibration characteristics of spindles is still insufficient. A dynamic characteristic computational model for high-speed aerostatic spindles with multiple degrees of freedom has been established, which incorporates the effects of multi-excitation coupling. This model accounts for the interactions and parametric transfers between the different spindle components and is grounded in the principles of fluid mechanics and rotor dynamics. The impact of factors such as external load excitations, rotational speeds, air supply pressures, and air film thicknesses on the nonlinear dynamic behavior of aerostatic spindles has been explored. Additionally, an experimental setup has been developed to monitor the nonlinear dynamic characteristics of high-speed aerostatic spindles. Through comparisons of dynamic responses, the accuracy of the computational model has been validated. The results of this study offer valuable theoretical insights that can support the advancement and application of high-speed aerostatic spindles in the realm of high-precision machining.</p>