Abstract: In recent years, we have been paying close attention to the silicone cationic emulsion, whose preparation method is simple and easy. But the relative fatal flaw of the process is the stability of the polymerization process. There will be serious "Floating Oil" phenomenon if controlled ineffectively. So this experiment will be conducted using D4 as the monomer, and KOH as catalyst composite emulsifier cyclosiloxane cationic polymerization. On this basis, we discussed detailedly the stirring speed, amount of catalyst, temperature, cationic emulsifier, nonionic emulsifier type, water-oil ratio on the polymerization rate, emulsion stability and the molecular weight. Finally, we have taken the optimization formula: the amount of emulsifier a is 6.9%, the amount of emulsifier b is 3.4%, the amount of emulsifier c is 2.9%, the amount of catalyst is 1% ( all relative weight ratio to monomer ),the mixing speed is 250rpm, the water-oil ratio is 120 to 70, the reaction temperature is 70℃.