Abstract: To elucidate the regulation mechanism of inorganic cations on the snap-on adhesion between bubbles and oil droplets, and to clarify the influence of inorganic cations with different valences and concentrations on the migration, adsorption, and liquid film stability of surfactants (sec-octanol), a combined approach of molecular dynamics (MD) simulation and macroscopic experimentation was employed. using sec-octanol as the surfactant, four inorganic cations of different valences (Na⁺, Ca²⁺, Mg²⁺, Al³⁺) were selected to prepare electrolyte solutions with various concentration gradients. the migration of sec-octanol clusters, uniform bubble generation, the bubble-oil droplet coalescence process, and the evolution of bubble internal pressure were systematically investigated. MD simulations were conducted via GROMACS software to construct box models of sec-octanol clusters and reagent migration. the ionic regulation mechanism was explored through radial distribution functions and energetic analysis. simultaneously, the entire snap-on adhesion process of bubbles and oil droplets was recorded using high-speed photography, pressure monitoring, and mechanical calculations to analyze the characteristics of bubble internal pressure and liquid film stability. The results indicate that electrolyte ions do not interact chemically with sec-octanol molecules directly; instead, they indirectly regulate the migration of sec-octanol clusters toward the gas-liquid interface by altering the water molecular network structure. specifically, trivalent Al³⁺ significantly promotes sec-octanol migration at all tested concentrations, whereas divalent Ca²⁺ and Mg²⁺ exhibit promotional effects only at high concentrations, and monovalent Na⁺ shows no significant effect regardless of concentration. During bubble-oil droplet coalescence, the internal pressure exhibits a two-stage decline: a slight pressure drop of approximately 22.5 Pa occurs during the interface reorganization stage, while the pressure change during the detachment stage aligns with the law of single bubble detachment. Surface tension gradients and fluid viscosity affect the surface pressure and dynamic pressure of the liquid film, respectively, jointly determining the coalescence process. The regulation patterns of internal pressure variations differ significantly among ions of different valences: in Ca²⁺ and Mg²⁺ systems, the pressure variation weakens with increasing concentration, whereas in the Al³⁺ system, it shows a trend of initially increasing and then decreasing. inorganic cations regulate the snap-on adhesion behavior at the bubble-oil droplet interface by modulating water structure, sec-octanol migration, and the physicochemical properties of the liquid film. this study clarifies the intrinsic correlations between ionic valence/concentration and interfacial behavior, liquid film stability, and bubble internal pressure, deepening the molecular-scale understanding of ion-regulated gas-liquid interfacial behavior.