<p>Stationary phase optimization is crucial for enhancing gas chromatography (GC) separation performance, yet coating process engineering remains overlooked despite its significant impact on stationary phase loading and distribution. Coating process engineering directly impacts the loading amount and the stacking mode of the stationary phase materials on the inner wall of the chromatographic columns. Uneven coating can result in insufficient stationary phase loading and severe material aggregation, ultimately preventing the material from achieving its full separation potential. Herein, we proposed a solvent polarity matching strategy and successfully fabricated an evenly distributed MIL-125-NH₂ stationary phase for GC separation. Compared to uneven stationary phases, the evenly distributed GC stationary phase obviously eliminated peak tailing in substituted benzene separation and demonstrated a remarkable improvement in separation resolution. Furthermore, validation with UiO-66 confirmed the universality of this strategy. This work established coating engineering as vital as material design, offering a practical approach to unlock the full separation potential of high-performance GC stationary phases.</p>