Abstract: To solve the problems of high ash in clean coal, low separation efficiency, and high flotation reagent consumption caused by the interference of high-ash fine slime during the separation of "lean, fine, and complex" coking coal in the Huainan mining area, the Panyi Coal Preparation Plant of the Coal Preparation Branch of Huaihe Energy Group proposed transforming the traditional “double-stage sieve bend + two-stage desliming flotation” process into a combined process of “tri-mass electromagnetic screen pretreatment + desliming tank deep desliming + two-stage flotation.” The structural composition and working principles of the tri-mass electromagnetic screen and desliming tank, as well as the process principle of two-stage flotation, are systematically introduced. Through on-site comparative experiments, the treatment effects of each process stage were explored; the process differences before and after the transformation, and the desliming and retention effects of the tri-mass electromagnetic screen versus the traditional double-stage sieve bend were compared; the optimization effect of the desliming tank on flotation feed and the separation efficiency of two-stage flotation were analyzed; combined with small-scale screening tests and production index monitoring, the feasibility and superiority of the process were verified. The results show that: compared with the double-stage sieve bend, the tri-mass electromagnetic screen has a better effect on removing high-ash fine slime and retaining coarse particles, with the oversize slime ash content reduced to 12.08%, the oversize yield of the >0.5 mm size fraction reaching 34.58%, and the coarse clean coal yield increasing from 27.33% to 31.04%; the desliming tank can efficiently remove <0.045 mm high-ash fine slime, with the yield of this size fraction in the overflow reaching 94.03%, and the underflow ash content being 1.79 percentage points lower than the feed; two-stage flotation can achieve efficient separation of clean coal, with the final clean coal ash reaching 10.52%, and the clean coal yield, combustible recovery, and flotation perfection index being 54.71%, 73.70%, and 56.56%, respectively; the second-stage flotation has a significant ash reduction effect on all size fractions of clean coal, especially in effectively removing fine-grained high-ash slime. The combined process of "tri-mass electromagnetic screen + two-stage desliming flotation" matches the separation requirements of high-argillaceous coking coal in the Huainan mining area. The synergistic effect of each process stage can achieve the comprehensive goals of "ash reduction, quality improvement, yield enhancement, and consumption reduction," solving the pain points of low separation precision and high reagent consumption in traditional processes. After process optimization, the annual saving in reagent costs is 200 000 yuan, with a net profit of 180 000 yuan, providing a replicable technical paradigm for the optimization and upgrading of coal preparation processes in similar mining areas.