Such interface-dominated food systems as plant protein-based emulsions and foams have some problems such as difficulty in preparation, environmental susceptibility and instability, which can be solved using a multi-dimensional strategy of “molecule-interface-droplets/bubbles” based on the interactions between saponins and plant proteins. This review summarizes the interactions in the water phase and at the interface of plant proteins and saponins and their adsorption and stabilization behaviors, and reveals the construction and stabilization of emulsion- and foam-based food systems and the relationship between them at the molecular level and from a macroscopic point of view in order to provide theoretical support for the preparation, stabilization and functional properties of plant-based interface-dominated foods.