Abstract: Flotation is a technology that separates and purifies materials in a three−phase flow of gas, liquid, and solid based on the differences in physical and chemical properties (mainly referring to wettability) of the material surface. It is widely used for mineral separation. Studying the basic flotation behavior, wettability, surface electrical properties, adsorption, and solution chemistry of minerals is a fundamental method for determining the interaction mechanism between flotation agents and mineral surfaces. However, for many complex flotation systems, various modern testing methods are required to characterize or prove these interaction mechanisms, and to reveal the essence of the interaction between flotation agents and mineral surfaces more clearly at the microscopic level. This article comprehensively analyzes the application and research status of imaging analysis techniques such as atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and surface composition analysis techniques such as Zeta potential, infrared spectroscopy, Raman spectroscopy, X−ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectrometry (TOF−SIMS) in flotation, providing reference for the better development of flotation interface testing in the future.