Present invention is related to an oil-in-water emulsion comprising a silicone mixture, a mixture of emulsifier having HLB value from 10 to 16, and the particle size of the silicone mixture in the emulsion is less than 350 nm. A method of preparing the said emulsion comprising mixing a trialkylsilyl terminated dialkylpolysiloxane of viscosity of from 40,000 to less than 100,000 mPa.s at 25° C. and an amino silicone of viscosity of from 1,000 to 15,000 mPa.s at 25° C. and amine value of from 2 to 10 mg of KOH per gram of polymer, at a temperature of 25° C. to obtain a mixed silicone fluid and emulsifying the mixed silicone fluid by using plurality of the non-ionic emulsifier to obtain an oil-in-water emulsion,wherein D50 particle size of less than 350 nm. The invention is to use the emulsion composition in the hair cosmetic composition.