The invention discloses a nanometer compound binary polymer pour point reducer and a preparation method thereof. The nanometer compound binary polymer pour point reducer is formed by compounding a nanometer material and a binary polymer pour point reducer through a solvent blending method. The method includes the following steps of esterifying methacrylic acid and multi-carbon alcohol, copolymerizing the product with maleic anhydride to obtain the binary polymer pour point reducer, and finally compounding the nanometer SiO2 material modified by a silane coupling agent KH570 with the binary polymer pour point reducer through the solvent blending method to obtain the nanometer compound binary polymer pour point reducer. The nanometer compound binary polymer pour point reducer is stable in performance and outstanding in effect, and the pour point reducing effect is further enhanced on the basis of pour point reducing of an existing binary polymer pour point reducer. When the pour point reducer is applied to 0# diesel oil, the filtering point and the condensation point of 0# diesel oil can be reduced by 10-17 DEG C and 24-35 DEG C respectively, and the pour point reducing effect is better than that of the existing binary polymer pour point reducer.