The invention belongs to the technical field of petroleum extraction, and relates to a method for quantitatively calculating the minimum miscible pressure of carbon dioxide (CO2) and in-place oil in the Ordos basin. The method is characterized in that the in-place oil in the Ordos basin is sampled, the fluid composition of the in-place oil is analyzed through a gas chromatography method, and the mole fraction Xvol of a volatile component, the mole fraction Xint of an intermediate hydrocarbon component and the average molecular weight Mc7+ of a heavy component of the in-place oil are obtained and substituted into the following formula to work out the minimum miscible pressure of CO2 and the in-place oil. By the adoption of the method for calculating the minimum miscible pressure of CO2 andin-place oil in the Ordos basin, simplicity and convenience are realized, high efficiency and rapidness are realized, and powerful evidences can be provided for development of CO2 oil displacement potential evaluation and block sieving in an oil field.