Screening method and system of thickening agent for CO2 oil displacement

According to the screening method and system for the thickening agent for CO2 oil displacement, the thickening agent for CO2 oil displacement matched with a target oil reservoir can be rapidly screened out, the screened thickening agent for CO2 oil displacement can remarkably increase the viscosity of CO2, the advantages of the CO2 oil displacement technology are further exerted, and the utilization rate and efficiency of CO2 are improved. Comprising the steps that solubility testing, viscosity testing, minimum miscible phase pressure testing, rock core damage testing and oil displacement effect testing are sequentially conducted on the to-be-screened thickening agents for CO2 oil displacement till the other thickening agent for CO2 oil displacement meeting the testing evaluation standard is left, the thickening agent for CO2 oil displacement suitable for a target oil reservoir is obtained, and screening is ended; and after all tests are completed, if multiple CO2 oil displacement thickeners meeting the test