The liquid-phase epitaxy (LPE) method was effectively implemented to deliberately grow/construct ultrathin (0.5–1 μm) continuous and defect-free ZIF-8 membranes. Permeation properties of different gas pair systems (O2–N2, H2–CO2, CO2–CH4, C3H6–C3H8, CH4–n-C4H10) were studied using the time lag technique.