Abstract: Froth flotation is an effective method for sorting fine-grained minerals.In the gas-liquid-solid phase system of flotation, the target mineral particles collide and adhere to the bubbles, which follow them rise to the foam layer.During the process of bubbles rising, some of the target mineral particles will be detached from the surface of bubbles into the pulp, thereby reducing the flotation recovery rate of the target mineral particles.The last step of the flotation process is to ensure that the target mineral particles are not detached.Since the 1960 s, particle-bubble detachment from the microscopic aspect has attracted the attention of scholars and been explored using different experimental methods.The research methods can be summarized into two categories: direct force measurement method and direct observation approach.Direct force measurement method mainly uses atomic force microscope(AFM) to test the detaching force between particle and bubble.Although accurate measurement of the interaction force is achieved, it cannot characterize the interface changes of the interaction between particles and bubbles in real time, and it is impossible to analyze the interaction between particle and bubble in all-dimensional and multi-angle.Direct observation approach uses high-speed camera to observe the detached process of particle-bubbles directly.Based on the use of high-speed cameras directly, the force measuring devices such as surface force meter and piezoelectric bimorph are used to directly measure the force between particle-bubbles.The method of vibration detachment is used to measure the critical detached force of particles and bubbles indirectly, the centrifugal motion of particles on the bubble surface is observed.The process of particle-bubble detachment in complex flow field is observed directly and the influence factors of complex flow on desorption are found.The direct observation method can observe the detached process of particle-bubble dynamically, and can characterize the interface changes of the interaction between particles and bubbles in real time, but how to accurately measure the dynamic mechanical changes between particle and bubble needs to be explored.