<p>When flow instabilities (such as rotating stall or surge) occur in centrifugal compressors, significant unsteady flow excitations are generated on the impeller surface. This may induce high alternating stresses, thereby compromising impeller operational safety. Experimental measurement of unsteady aerodynamic pressures on impeller surfaces remains challenging and costly, particularly under high-speed conditions. Moreover, numerical studies on complex 3D impeller blade aerodynamic loads in compressors are often prohibitively time-consuming and typically generate data requiring substantial storage resources. To address these challenges, this study developed a rapid and accurate predictive method for impeller surface aerodynamic pressure by establishing a simplified model and a parametric model. Results demonstrate that the relative errors in aerodynamic pressure between the simplified/parametric models and the actual model at corresponding positions are below 6%. This enables fast and precise prediction of impeller surface aerodynamic loads without numerical simulation. Furthermore, the parametric models were utilized to explore the influence law of different flow conditions on unsteady aerodynamic loads on the impeller surface. The proposed prediction method provides a low-cost solution for acquiring unsteady aerodynamic loads on impellers, offering significant engineering applicability.</p>