Abstract:This review outlined the recent progress and application prospects of micro-nano bubbles' （MNBs， 1 nm-100 μm） in mineral flotation. The preparation methods，characterization techniques，mechanisms，and engineering practices of MNBs were systematically summarized. Owing to their high surface area，long residence time，surface charge，and superior gas-liquid mass transfer，MNBs improved particle collision and attachment， promote aggregation，and enhance surface hydrophobicity. These effects led to higher recovery of fine-grained minerals and reduced reagent consumption in complex systems. The merits and limitations of hydrodynamic cavitation，dissolved gas release，electrochemical，and ultrasonic methods were compared，and optical imaging， AFM，and Zeta potential analysis for bubble characterization were discussed. Representative applications in metallic， non-metallic，coal，and secondary resources were highlighted，emphasizing the differences in flotation performance. The dual roles of MNBs in flotation，including enhancement （e.g.，capillary bridging） and suppression （e.g.， interfacial cleaning，entrainment reduction），were analyzed together with key influencing factors such as particle size， reagent type，bubble distribution，and hydrodynamics. Current challenges remained in balancing bubble stability with energy demand，clarifying the underlying mechanisms，and achieving uniform distribution at scale. Future directions point to targeted interfacial regulation，multi-field coupling，and green intelligent preparation to promote efficient， low-energy，and controllable industrial flotation.