In order to realize the efficient separation and capture of CO2 in humid flue gas, Organic amine polymer (TP) was coated on the surface of metal organic framework (MOFs) material MIL-101(Cr) by supramolecular assembly method, and then polydimethylsiloxane (PDMS) was deposited on the outer surface of the material by vapor deposition method. Hydrophobic core-shell composite MIL-101(Cr)@TP-PDMS was constructed and used for the adsorption and separation of CO2 in humid flue gas. The structure, morphology and thermal stability of MIL-101(Cr)@TP-PDMS were characterized and tested by FTIR, XRD, SEM, TEM, EDS and TGA. The separation and adsorption selectivity of MIL-101(Cr)@TP-PDMS for CO2/N2 (volume ratio 15:85) mixture was evaluated by adsorption experiments. Based on the breakthrough experiment, the effects of different relative humidity and gas flow rate on the adsorption capacity of CO2 and the cyclic adsorption stability of MIL-101(Cr)@TP-PDMS were investigated. The results showed that the specific surface area (1432 m2/g) and pore volume (0.713 cm3/g) of MIL-101(Cr)@TP-PDMS decreased compared with that of MIL-101(Cr) (2342 m2/g and 1.172 cm3/g), but there was no change in pore size distribution; a layer of about 10 nm of encapsulated CO2 on the outer surface of MIL-101(Cr)@TP-PDMS was attached a coating layer of about 10 nm; The CO2 adsorption capacity (38.28 cm3/g) and CO2/N2 separation and adsorption selectivity (388) of MIL-101(Cr)@TP-PDMS were improved by the hydrogen bonding between the imine bond of the coated TP and CO2, which were 1.7 times and 31.3 times of the CO2 adsorption capacity (22.5 cm3/g) and CO2/N2 separation and adsorption selectivity (12.4) of MIL-101 (Cr); The deposited PDMS realized the hydrophobic modification of MIL-101(Cr), and the water contact angle increased from 26.6° of MIL-101(Cr) to 134.9° of MIL-101(Cr)@TP-PDMS, which made MIL-101(Cr)@TP-PDMS maintain CO2 / N2 separation and adsorption selectivity and CO2 saturated adsorption capacity (38.28 cm3/g) under different relative humidity (40%~80%) conditions, and the performances were stable after 15 dynamic breakthrough tests.