This study investigated the synergistic effect of viscosity regulators (polyethylene glycol, sodium carboxymethyl cellulose, and polyacrylamide) and frother (2-octanol) on upgrading the flotation performance of low-rank coal. The results of flotation tests were consistent with the analysis of induction time and supported by the results of SEM, viscosity, foaming ability, and foam layer stability. In the present work, it was observed that the highest combustible matter recovery was obtained by mixing the polyethylene glycol (PEG300) with 2-octanol, which increased from 32.9% to about 64.4% accompanied by a little increase of ash content (0.54%). Therefore, it demonstrated that the combination of PEG300 and 2-octanol provided the highest combustible matter recovery and better flotation selectivity.