Abstract: Inhibitors are important for flotation separation of quartz and feldspar. In this study, a novel combined inhibitor was used to separate quartz and feldspar in near-neutral pulp. Selective inhibition of the combined inhibitor was assessed by micro-flotation experiments. And a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening mechanism. The outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca²⁺ and SS in sequence under the optimal proportion of 1:5. A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired, and was found to be 90.70wt% and 83.70%, respectively. It was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared (FT-IR) and adsorption capacity tests. The results of X-ray photoelectron spectroscopy (XPS) indicated that Ca²⁺ directly interacts with the surface of quartz to increase the adsorption of collectors. In contrast, the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na⁺ and Ca²⁺ taking the place of K⁺, resulting in the composite inhibitor forms a hydrophilic structure, which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active site. The combination of Ca²⁺ and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector, thus achieving the effect of efficient separation. A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.