Cavity-filling　is　a　common　phenomenon　whereby　a　fluid　fills　all　or　part　of　a　cavity,　displacing　another　immiscible　fluid.　In　this　study,　we　experimentally　and　theoretically　investigate　the　effects　of　the　cavity　aspect　ratio,　channel　width,　tilting　angle　of　the　cavity　leading　wall,　and　inlet　flow　rate　on　the　morphology　of　the　water-air　interface　and　the　filling　fraction　of　various　cavities.　Considering　the　influencing　factors,　we　derive　two　formulas　for　predicting　the　filling　fraction,　and　verify　these　expressions　against　experimental　results.　The　findings　of　this　study　provide　theoretical　guidance　for　applications　related　to　pressure-driven　filling　of　cavity　structures.　Published　under　an　exclusive　license　by　AIP　Publishing.