The motion behavior of sand particles in inertial particle separators has garnered increasing attention, with aerodynamic characteristics serving as a critical foundation for understanding their trajectories. Conventional drag measurements based on free-settling methods primarily focus on regular-shaped particles, failing to capture the complex aerodynamic behavior of irregular-shaped sand particles. Moreover, such methods suffer from inherent limitations: (1) Uncontrolled particle orientation during settling prevents inflow angle adjustment; (2) Measurements are restricted to drag forces, excluding lift and lateral components; (3) Inability to control settling velocity hinders accurate Reynolds number regulation. To overcome these issues, a three-component aerodynamic measurement method and a corresponding experimental system were developed for irregular-shaped sand particles. Six representative particle models were selected to reflect typical geometric features. By adjusting the installation orientation, controlled variations in angle of attack and sideslip angle were achieved. A six-component balance enabled simultaneous measurement of drag, lift, and side forces, facilitating systematic analysis of the effects of Reynolds number, sphericity, and inflow angles. Results show: (1) Reynolds number is the dominant factor affecting drag, with drag coefficient decreasing as Reynolds number increases; (2) Particle shape ranks second in influence—particles with lower sphericity exhibit significantly higher drag; (3) Inflow angle is a secondary factor, with drag increasing under larger angles, especially for low-sphericity particles; (4) Sideslip angle has a stronger impact than attack angle due to its induction of asymmetric three-dimensional flow. Finally, a drag coefficient correlation was established based on experimental data, incorporating Reynolds number, sphericity, and inflow angles to support future multi-parameter aerodynamic modeling.