The invention discloses a preparation method of a microarc oxidation layer of a graphene doped titanium alloy drilling rod. The preparation method adopts an electrolytic solution containing graphene to carry out microarc oxidation treatment on a titanium alloy drilling rod. An electrolytic solution comprises 0.5-6g/L of graphene, 2-10g/L of Na2SiO3, 1-5g/L of glycerol, and 1-8g/L of (NaPO3)6; andthe electrolytic solution is prepared with deionized water and the total volume is 3 liters. The temperature of the electrolytic solution is controlled at 25-30 degrees. Technological conditions for microarc oxidation are as follows: the current density is 2-10 A/dm2, the duty ratio is 20-60%, the oxygenation time is 10-60 min and the frequency is 100-600 Hz. After the microarc oxidation treatmentis carried out on the titanium alloy drilling rod after the graphene is added, the wear-proof, anti-corrosion and anti-sticking performance of the surface of a film layer is improved, the life of thedrilling rod is prolonged, the safety of well drilling is further improved, the production cost is lowered, and the preparation method has important social value and economic value.