<p>Rotating machinery is a crucial component in modern industrial systems, offering high efficiency and reliable performance. However, vibration issues significantly shorten their operational lifespan. Squeeze film dampers (SFDs), due to their simple structure, low cost, and effective vibration reduction, are widely used in these systems. However, the strong nonlinearity of SFDs means existing designs often rely on trial-and-error methods. This study focuses on optimizing damper parameters, particularly the clearance ratio, which is a key design factor. A numerical model based on kinetic equations and elastic supporting vibration theory is developed to explore the relationship between damper transmissibility and speed coefficient across different clearance ratios. The impact of clearance ratio on squeeze film dynamics is further examined through experimental tests on a rotor-SFD system. Results show that at a clearance ratio of 0.3%, a stable squeeze film forms, minimizing two-phase flow effects and maximizing film carrying capacity. This research provides valuable insights into enhancing the efficiency of damper designs in rotating machinery.</p>