In this study, a facile method was developed to fabricate MoS2 nanosheet-enhanced Pebax-MoS2 mixed matrix membranes (MMMs) for CO2 capture. A super mixer was introduced to ensure the homogeneity of the as-prepared solutions, and a far more efficient method of Pebax-MoS2 MMM preparation was accordingly achieved. The membrane structures were observed by SEM, and membrane crystallinity was examined by XRD and DSC. FTIR and Raman spectroscopy were utilized to verify that the Pebax-MoS2 membranes were well prepared. The gas permeability results showed that the Pebax membrane doped with 4.76 wt % MoS2 nanosheets had the best performance, with a CO2 permeability of 67.05 Barrer and CO2/N-2 selectivity of 90.61. The molecular simulation technique used for the Pebax-MoS2 MMMs was first adopted by our group to investigate CO2 solubility and CO2/N-2 solubility selectivity. The simulation results demonstrated the strong affinity of CO2 for the added MoS2, consequently contributing to high CO2/N-2 selectivity, and were highly correlated with the experimental results. Pebax-1657-based MMMs incorporating MoS2 nanosheets can be therefore be considered a promising alternative for CO2 capture applications.