Because CO2 flooding can meet the demand of both environmental protection and enhanced oil recovery，it has attracted increasing attention. The reservoir screening and potential evaluation methods of CO2 flooding are the basis of medium and long-term development planning and large-scale field application，but the screening criteria guided by miscibleimmiscible flooding theory are difficult to adapt to China’s continental sandstone reservoirs. Therefore，the miscibility characteristics of CO2 flooding are firstly studied by numerical simulation. The transient miscibility at the initial injection end appears. Afterwards，the miscibility zone moves to the production end，and phenomena including phase separation，interfacial tension reduction at leading edge and interfacial tension rise in the production well appears. The variation characteristics of miscibility degree are analyzed and the boundaries of near-miscibility flooding are proposed. On the basis of existing standards，a new standard for screening CO2 flooding reservoirs is proposed. It is combined with fuzzy evaluation and analytic hierarchy process，and a screening method for CO2 flooding in sandstone reservoirs is proposed and applied to the screening of CO2 flooding reservoirs of SINOPEC. The results show that SINOPEC has 2.262 billion tons of proven reserves suitable for CO2 flooding except for chemical flooding reservoirs and heavy oil reservoirs，of which，489 million tons are miscible flooding，659 million tons are near miscible flooding and 1 114 million tones are immiscible flooding，and the recoverable reserves are expected to increase by 203 million tons.