The invention relates to the technical field of petroleum base lubricant composition and a preparation method thereof, which is copper and aluminum wire drawing oil and a preparation method thereof. The copper and aluminum wire drawing oil comprises base oil, an emulsifying agent, an auxiliary emulsifying agent, a defoaming agent, an antirusting agent, a preservative and an antiwear agent. The preparation method can be carried out by the following steps that: the copper and aluminum wire drawing oil is mixed into 3 percent to 45 percent of water-based emulsion according to the weight percentage. The water-based emulsion is showered into a wire drawing die cavity in the copper and aluminum wire drawing process. The product of the invention has good lubricating property, excellent light stability and storage stability, low cost, good cooling effect, fast heat-transfer speed, little temperature-rise amplitude, nonflammability and easy cleaning, thus guaranteeing safety of use environment. Copper wires and aluminum wires which are drawn by adopting the product have even line shapes, bright surfaces, and rustless property, and also have good ultraviolet and storage stability and good stability.