Accurate measurement of CO2 flow is fundamental to the large-scale advancement of CCUS projects and the basis for bulk carbon trading measurement. However, the industrial captured CO2 often contains a variety of impurities, and its complex phase characteristics and nonlinear characteristics of density changing with temperature and pressure make the measurement results highly sensitive to the fluctuation of working conditions, which seriously affects the accuracy and stability of flow measurement. Based on flow measurement and the physical properties of supercritical/dense-phase CO2, the influence of impurity components on the density and phase characteristics of CO2 gas sources containing impurities were studied, as well as the high cost of mass flow meters and the limitation of large pipe diameters. In view of the above flow measurement problems of CO2 containing impurities, the GERG-2008 equation of state suitable for engineering use, was used to calculate the physical parameters of CO2 containing impurities, and the single-phase control are proposed. MATLAB and REFPROP software are used at the same time. The density correction model covering the pressure range of 7.3~20.3 MPa and the temperature range of -20~120 ℃ was established, and the accurate measurement technology of CO2 mass flow with impurities based on density correction was formed. By comparing the calculated value of the model with the reference result of Coriolis mass flow meter, the relative error of mass flow rate is within ±2%, which meets the maximum error requirement of the first-level metering system in the industry standard. The accurate mass flow measurement technology based on density correction effectively overcomes the influence of impurity components on the phase and physical properties of CO2, and demonstrates the advantages of low cost, high precision, and strong adaptability. The formed accurate measurement technology of mass flow rate with single phase control and density correction as the core provides a theoretical basis for the accurate measurement of CO2 mass flow containing impurities, and also provides an economical and reliable solution for the safe operation of CCUS projects and the fair development of bulk carbon trading, contributing to the realization of the carbon peaking and carbon neutrality goals in China.