Abstract: As the primary energy source in China, coal plays a crucial role in national energy security. More than two-thirds of coal reserves are distributed in arid and water-scarce regions. Low-quality coal accounts for approximately 40% of total resources. With the widespread application of fully mechanized mining, the production of fine coal ( < 6 mm) has increased to more than 40% of raw coal. Although dry separation technologies for ≥6 mm coarse coal have achieved stable industrial application in several mining areas, the separation accuracy for < 6 mm fine coal remains limited. In addition, hydraulic fracturing and water spraying for dust suppression during mining substantially increase the moisture content of raw coal (above 15%), leading to pronounced particle agglomeration. These factors highlight the need to develop effective dry separation theories and technologies for moist and low-quality fine coal. The performance constraints of gas-solid fluidized separation and vibration-air synergistic separation technologies that have been utilized in industrial applications are examined. Based on flow responses, interface formation mechanisms, and equipment adaptability under conditions of moist low-quality fine coal, several key scientific questions are summarized. These include density-stratification regulation and multiscale flow coupling in gas-solid fluidized separation, controllable construction of stable force fields for vibration-air synergistic separation of low-quality fine coal, and nonequilibrium thermos-hydrodynamic coupling mechanisms governing moisture removal from wet particles. The numerical simulations and theoretical models from experimental studies are synthesized, concerning fine dense-medium gas-solid fluidized separation, vibration-air synergistic separation, fluidized-bed drying, and transient steam flash drying. For fine dense-medium gas-solid fluidized beds, findings related to bed expansion, pressure fluctuations, bubble dynamics, and electrical capacitance tomography (ECT) are summarized with corresponding flow-regime criteria, density-control correlations, and quantitative instability indicators. For vibration-airflow synergistic separation, the researches are reviewed on vibration acceleration responses, the evolution of surging structures, three-dimensional particle dynamics, interface formation behavior, and parameter combinations involving high-frequency vibration and stepped air distribution. For drying processes, studies on liquid-bridge mechanics, heat and mass transfer under vibration-airflow coupling, nonequilibrium thermodynamic drying models, and the energy distribution and moisture-migration characteristics during saturated-steam pressurization followed by rapid depressurization are synthesized. Building on these findings, the processes of drying, dry screening, and dry separation are reorganized to summarize and discuss an integrated “drying-dry screening-dry separation” beneficiation approach for < 6 mm fine coal. In this scheme, moderate drying reduces liquid-bridge adhesion, dry screening forms a narrow size-fraction feed, and gas-solid fluidized or vibration-airflow synergistic separators accomplish dry separation, thereby expanding the applicability of dry beneficiation to a broader range of coal types and particle sizes. Overall, existed studies have established a preliminary foundation in multiscale coupling mechanisms, quantitative characterization of flow stability, and integrated design of drying and separation. The further progress is needed in multiphysics coupling under complex operating conditions, intelligent monitoring and adaptive control, and the integration of dry beneficiation with waste-heat recovery and carbon-reduction objectives. That provides references for future research and process optimization related to the efficient dry upgrading of fine coal.