Kaolinite is widely used in papermaking, ceramics and other industries, but its high-value applications are limited by gangue minerals and lattice impurities (e.g., Fe, Ti). Flotation, a key purification technique, is hindered by conventional collectors’ poor selectivity and weak affinity. This review classifies collectors into anionic, cationic, mixed and novel types, analyzes key influencing factors (mineral interfacial properties, reagent structure, solution chemistry, process parameters) and elucidates their interaction mechanisms with kaolinite. Current research focuses on conventional kaolinite, while coal-measure kaolinite - abundant but with complex processing challenges - lacks attention. Its inefficient beneficiation stems from insufficient understanding of lattice impurity genetic characteristics, leading to non-targeted collector design. Future studies should prioritize coal-measure kaolinite, decode its lattice impurities, and use machine learning to screen targeted chelating collectors. Establishing a genetic coupling model will guide efficient flotation separation, improving kaolinite purity for high-end applications.