CO₂ pre-pad fracturing is a very promising reservoir stimulation method, possessing the advantages of excellent energy enhancement, fast flowback, low formation damage. The influences of reservoir parameters such as capillary pressure and matrix permeability, and engineering parameters such as soaking pressure, soaking time, flowback rate and flowback pressure on the flowback efficiency of CO₂ pre-pad fracturing in shale reservoirs were investigated using numerical simulation methods, and the influence mechanism of each parameter was analyzed. The results show that the lower the values of reservoir permeability and capillary force, the higher the fracturing fluid flowback resistance and the lower the flowback rate. The influence of permeability on the CO₂ storage effect is more significant. The influence of capillary force on the fracturing fluid flowback rate is negligible. Engineering factors affect the effectiveness of fracturing fluid flowback primarily through the effective accumulation of CO₂ energy and the retention of fracturing fluid due to leakage and filtration losses. The optimized range of parameters resulted in an increase in fracturing fluid flowback rate of more than 5% and an increase in recovery rate of more than 7%. Energy storage of CO₂ pre-pad in this regime can not only provide sufficient energy for reservoir return and production, but also improve the range of pore mobilization and increase crude oil recovery.