The invention discloses a low-temperature-resisting crude silicon rubber which is obtained by polymerizing octamethyl cyclotetrasiloxane (D4), hexaethylcyclotrisiloxane (D3Et), 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane (D4Vi), a catalyst and an accelerating agent and then heating, removing small molecular low-boiling-point substances in materials in vacuum and cooling to room temperature. According to the invention, the low-temperature-resisting crude silicon rubber product disclosed by the invention is stable, the glass transition temperature (Tg) of the rubber is low and is not crystallized at low temperature; polymerization process is simple and does not need a solvent, and the high-molecular-weight low-temperature-resisting crude silicon rubber can be obtained through severely controlling reaction conditions in short reaction time; and the rubber is high in yield, controllable in molecular weight, simple in posttreatment and easy to produce in a large scale.