Wettability is a significant factor affecting the oil recovery factor of gas flooding. In order to enhance oil recovery, it is of great importance to choose appropriate CO2 injection methods for oil reservoirs with different wettability. NMR technique and physical simulation experiment were combined to investigate the microscopic residual oil distribution after CO2 injection in the low-permeability cores with different wettability. The influence of wettability on the displacement characteristics of different CO2 injection methods was discussed. The results suggested that the continuity of oil distribution in pores is an important factor affecting the effect of CO2 flooding. The more oil-wet of the reservoir wettability is beneficial for the CO2 to dissolve into the oil and displace the oil. Therefore, each CO2 injection method could get better displacement efficiency which were over 70% in oil-wet reservoirs. For water-wet reservoirs, CO2 flooding after water flooding could have better displacement efficiency and injectivity. And for mixed wet reservoirs, WAG could have better displacement efficiency.