The formation natural energy of deep low permeability glutenite reservoir is relatively low, and the productivity decreases rapidly after fracturing. Moreover, due to the strong formation water sensitivity and heterogeneity, the effect of water injection development is poor and the recovery degree is low. In order to further improve the development efficiency of this kind of reservoir, the experimental research on enhanced oil recovery by CO2 huff and puff was carried out. The effects of production pressure, soak time, huff and puff cycle and core permeability on huff and puff recovery were analyzed. Combined with NMR analysis experiment, the micro pore production characteristics of CO2 huff and puff were studied. The results show that the lower the production pressure and the longer the soak time, the higher the recovery efficiency of huff and puff. With the increase of huff and puff cycle, the recovery and oil change efficiency of cyclic huff and puff gradually decrease. The higher the permeability of the core, the higher the recovery of huff and puff in different cycles. The optimal production pressure of CO2 injection huff and puff is 26 MPa, the optimal soak time is 8 h, and the optimal huff and puff cycle is 5 times. The pore structure of the core has obvious influence on the micro production characteristics of crude oil during CO2 huff and puff, for the cores with less macro-pores and poor physical properties, the crude oil in macro-pores is mainly used in the initial stage of huff and puff, while the contribution of recovery factor in the later stage of huff and puff mainly comes from small pores, and the overall recovery degree of such cores is low. For the cores with more macro-pores and better physical properties, the production degree of crude oil in macro-pores is always higher than that in small pores, and the overall recovery degree is high. After the implementation of CO2 injection huff and puff measures in S-1Y well, the daily oil production has been significantly increased, the water cut has been significantly reduced, and a good oil increasing effect has been achieved. [ABSTRACT FROM AUTHOR]