Silicon carbide quantum dots (QDs) were prepared by controllable chemical etching method, and then the aqueous solution of SiC QDs were obtained by ultrasonic cavitation and high-speed chromatography, the surface physicochemical properties of SiC QDs were controlled by chemical coupling method. The microstructure and spectral properties of SiC QDs were characterized by adjusting the preparation parameters, the results show that the main factors affect the relative photoluminescence intensity of SiC QDs are corrosion times, composition of corrosive agent and corresive agent components. Adjusting the corrosion times and the proportion of corrosive agent components, then analysis pure sulfuric acid of coupling agent is added, the relative photoluminescence intensity of water-phase SiC quantum dots is the best when V(HF)∶V(HNO3)∶V(H2SO4)=6∶1∶1 is used to corrode the milled β-SiC powder. At the same time, the formation mechanism and modification stability of -SH on the surface of SiC quantum dots are studied and analyzed.