In order to reduce the energy consumption of crude oil transportation, combined with the characteristics of Daqing high-wax crude oil, azobisisobutyronitrile (AIBN) was used as initiator, maleic anhydride (MAH) was grafted onto ethylene-vinyl acetate copolymer (EVA) by chemical grafting method to prepare EVA-g-MAH(EVAM) polymer pour point depressants(PPDs). The effects of EVAM polymer PPDs synthesized under different conditions on the pour point and viscosity of the model oil were investigated. And by optimizing the reaction conditions, the changes of the model oil wax crystal morphology before and after the addition of additives were explored. The research results show that when EVA with the VA mass fraction of 33% is selected, the AIBN content is 0.3% of monomer mass, mEVA:mMAH=1:5, the reaction temperature is 60 ℃, and the reaction time is 5.5 h, the pour point of the model oil can be reduced from 34 °C to 17 °C, and the viscosity at 32 °C can be reduced from 2399 mPa·s to 4.8 mPa·s, when doped with 600 mg/kg of EVAM at 21 ℃, the viscosity of the model oil was only 837.4 mPa·s, which is further reduced by 67.86% compared with the model oil with the same dose of EVA (wVA=33%). Combined with polarized light microscope analysis, it is shown that the addition of EVAM PPDs interferes with the growth direction of wax crystals in the model oil, further improves the dispersion between wax crystals, makes it difficult to form a three-dimensional network structure, and improves the flow of the model oil at low temperatures.