Abstract: Compared with traditional reagents (hydrocarbon oil), the emulsified collector has high dispersion in water due to reduce the interfacial tension between oil and water. It can be quickly and selectively adsorbed on the coal surface for improving the hydrophobicity of the coal surface to enhance the flotation efficiency. The problems of poor collection performance, poor selectivity and high fuel consumption in coal flotation can be effectively solved. The structure and formation mechanism of emulsified collector (common emulsion and microemulsion) are introduced. The advantages and disadvantages of mechanical stirring, ultrasonic emulsifying and jet emulsifying methods for preparing emulsified collector are analyzed. The relationship between the dispersibility, surface modification, flotation rate of emulsified collector and the improvement of coal slime flotation efficiency is described. The current research types and applications of emulsified collectors are summarized. It is pointed out that the design and preparation of emulsified collectors with different characteristics according to the properties of coal slime will be beneficial to promote the efficient recovery of coal slime on industrial scale.