Large caves，water-eroded pores and cracks are the main reservoir spaces of fractured-vuggy carbonate reservoir with complicated connectivity pattern and strong heterogeneity. CO2 huff and puff and CO2 displacement are effective productive method，which can improve development effect by supplying formation energy and reducing oil viscosity through dissolved CO2 in oil. According to the field geological data，a 3D simulation physical model was designed and used in laboratory experiment to simulate the typical fractured-vuggy reservoir units，and a series of laboratory experiments were carried out to simulate CO2 huff and puff and CO2 displacement processes. The dynamics of production was analyzed. The stimulation effect of CO2 huff and puff in high and low position was researched and the recovery percentage in high or low position with CO2 huff and puff and CO2 displacement was compared. On this basis，the mechanism of gas injection and oil displacement in the fractured-vuggy reservoir was analyzed. Experimental results show that the EOR of CO2 huff and puff in high position is 16.09% higher than that in low position due to the interaction between bottom water and secondary gas cap and the advantage of well location. Taking advantage of the different controlling areas of gas，the oil recovery of CO2 huff and puff in high and low position is 8.07% and 5.01% higher than that of CO2 displacement，respectively. The effect of CO2 huff and puff is superior to that of CO2 displacement.