Molecular dynamics (MD) and Monte Carlo (MC) simulation techniques were used to investigate the structural characteristics and transport behavior of PIM-Trip-TB and KAUST-PI-1 membranes. Potential in gas separation processes, the PIM-Trip-TB and KAUST-PI-1 membranes are composed of shape-persistent bridged Triptycene (Trip) unit. The effect of the Triptycene unit on the membrane structure, mechanical strength and gas transport behavior was analyzed in this study. Compared to PIM-PI-1 which consists of a less rigid spirobisindane (SBI) unit, the PIM-Trip-TB and KAUST-PI-1 revealed larger surface area, higher fraction free volume, higher value of Young’s modulus, and narrower distribution of dihedral angles. Furthermore, the membrane transport properties were evaluated by investigating the adsorption isotherm and self-diffusion behaviors of various gases within the membranes. The simulation results agreed well with the experimental data, demonstrating combined MD and MC techniques are a reliable tool for the characterization of membranes.