Silicone oil of dimethyl polysiloxane was synthesized from 70 % ferrosilicon. The steps were divided into the preparation of methyl chloride from the reaction of methyl alcohol and hydrogen chloride gas, the preparation of methyl chlorosilane by the reaction between methyl chloride and ferrosilicon using copper powder as a catalyst, the separation of methyl chlorosilane, and the hydrolysis and polymerization of methyl chlorosilane. Each step was discussed in detail in terms of the reaction conditions such as the effects of reaction temperature, reaction time, catalyst, and promotor on the synthesis processes. Finally, dimethyl polysiloxane oil of different viscosity range was obtained.