In this study, the effect of adding NaCl on the flotation enhancement mechanism of low-rank coal was investigated. A gradual reduction in the negativity of the zeta potential of low-rank coal with NaCl addition was conducive to reducing the bubble-particle attachment time and enhancing low-rank coal recovery. In addition, the reduced bubble size and improved foam stability with NaCl addition were moderately beneficial to coal recovery. The flotation rate constant, k, and the maximum combustible recovery, epsilon, increased remarkably as the NaCl concentration increased, indicating that the flotation kinetic of low-rank coal was enhanced by the addition of NaCl.