Aiming at the phenomenon that asphaltene deposition is easy to occur in the process of CO₂ injection to enhance oil recovery，the damage characteristics of asphaltene deposition on tight sandstone reservoir during CO₂ huff and puff were studied by using CO₂ huff and puff and nuclear magnetic resonance. The experimental results showed that，the higher the asphaltene content in the oil sample，the greater the asphaltene deposition rate in the process of CO₂ huff and puff. With the increase of experimental pressure，the asphaltene deposition first increased and then decreased，and the asphaltene deposition rate reached the maximum when the pressure was 25 MPa. The damage degree of asphaltene deposition to reservoir permeability was greater，while the damage degree to porosity was relatively small during CO₂ huff and puff. The asphaltene mainly deposit in the bigger pores， moreover，the higher the asphaltene content of the crude oil，the greater the damage degree of the bigger pores. The asphaltene deposition could make the wettability of the inlet core edge change from hydrophilic to the lipophilic. The asphaltene deposition would affect the oil recovery during CO₂ huff and puff，the greater the asphaltene content，the lower the oil recovery. In the process of CO₂ huff and puff in tight sandstone reservoir，the corresponding measures should be taken to restrain asphaltene deposition，so as to improve the effect of CO₂ huff and puff.