Abstract: CO₂ transportation, as the intermediate link of CO₂ capture, usage and storage (CCUS) technology, undertakes the important task of transferring CO₂ from capture to storage point. Combined with the experience of crude oil and natural gas pipeline, it can be seen that pipeline transportation has high safety and reliability because of its large volume of transportation. The pipeline transportation has strong continuity and other advantages, which is the most important way to transport CO₂. According to the experience of CO₂ pipeline transportation in foreign countries for more than 40 years, supercritical-dense phase CO₂ was considered to be the most economical pipeline transportation mode because of its high density similar to liquid and high diffusivity and low viscosity similar to gas. Taking the 300 000 t/a CCUS project of a domestic oil field as an example, the supercritical dense phase CO₂ pipeline with different pipe diameters was simulated and calculated under the same inlet parameters by using Pipephase simulation software, and the pipeline pressure and temperature under different pipe diameters were analyzed and studied. According to the variation of density and transportation distance, the optimum transportation parameters of supercritical dense phase CO₂ containing impurities were obtained, which provided a theoretical basis for the extension and development of CCUS projects in China.