Oil composition for cold rolling process of non-chlorine system seamless stainless steel tube and preparation method of oil composition

The invention discloses an oil composition for a non-chlorine system seamless stainless steel tube cold rolling process, which is prepared from the following components in percentage by mass: 60 to 80 percent of base oil, 5 to 10 percent of ammonium phosphate, 5 to 10 percent of extreme pressure agent, 6 to 12 percent of ammonium borate, 3 to 7 percent of macromolecular polyester, 0.1 to 0.3 percent of antioxidant, 0.4 to 1 percent of antirust agent and 0.1 to 0.5 percent of corrosion inhibitor. The sum of the mass percentages of the raw materials is 100%. The invention also discloses a preparation method of the composition, which comprises the following steps: adding the ammonium phosphate, the extreme pressure agent, the ammonium borate, the antioxidant, the antirust agent and the corrosion inhibitor into a stirring kettle containing the base oil, stirring until the materials are dissolved, then adding the high-molecular polyester, heating and stirring until the materials are completely dissolved, and filte