Abstract: Methanol, as an emerging energy source, has an important position in the energy transition. Sequential methanol transport through the refined oil pipeline can not only reduce the cost of transporting methanol over long distances but also alleviate the problem of low throughput of refined oil pipeline. In the process of sequential delivery, miscible liquids will inevitably be generated, and the miscible characteristics of methanol-oil products play a key role in the separation and treatment of miscible liquids. In this paper, a liquid-liquid phase equilibrium experimental device was designed and constructed independently, and the effects of alcohol/oil ratio, water content and temperature on the phase solubility of the blended system were analyzed to obtain the changing law of methanol content in refined oil under different conditions. It was found that, in the temperature range of -10~50℃, the phase solubility of methanol and gasoline was better, but due to the polarity difference, the mixed system was easy to phase separation when the temperature was lowered or the water content of methanol was increased; and the phase solubility of methanol and diesel fuel was poor, and it was difficult to completely dissolve. In addition, lowering the temperature and increasing the water content of methanol can significantly reduce the solubility of methanol in the product oil; with the increase of the alcohol-oil ratio of the blended system, the content of methanol in the gasoline/diesel fuel layer showed a tendency of increasing and then decreasing, and reached the peak value at 30% and 50% of the volume fraction of methanol, respectively. This study analyses the changing law of methanol content in refined oil under different conditions, and provides important theoretical guidance and basis for the prediction of methanol blending and blending treatment process for sequential delivery of refined oil pipeline.