Silicone oil is a kind of polyorganosiloxane with chain structure with different polymerization degrees. It is obtained by hydrolyzing dimethyldichlorosilane with water to obtain the primary polycondensation ring body. The ring body is cracked and rectified to obtain the low ring body, and then the ring body, the capping agent and the catalyst are put together to obtain each A mixture of different polymerization degrees can be obtained by vacuum distillation to remove low boiling substances.