NOVELTY - Absorption and hydration coupling device used for separating ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas comprises supercharger exhaust pipe (B1), first heat exchanger (B2) having an outlet connected with heat balance tank (B3), which has air outlet pipe connected with absorption tower (B4), hydration reactor (B12) connected with hydration decomposition tank (B13), desorption tower (B5), which has top liquid inlet connected with bottom liquid outlet of absorption tower, rectification tower (B6), and second heat exchanger (B15).    USE - Absorption and hydration coupling device used for separating ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas (claimed).    ADVANTAGE - The device achieves high separation efficiency in a high concentration area via absorption method and high separation efficiency in a low concentration area via hydration method, and reduces the solvent amount required by the absorption method. The purity of the obtained ethylene product reaches 99.6%; and the ethylene product can directly enter an ethylene tower.    DETAILED DESCRIPTION - Absorption and hydration coupling device used for separating ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas comprises supercharger exhaust pipe (B1), first heat exchanger (B2) having an outlet connected with heat balance tank (B3), which has air outlet pipe connected with absorption tower (B4), hydration reactor (B12) connected with hydration decomposition tank (B13), desorption tower (B5), which has top liquid inlet connected with bottom liquid outlet of absorption tower, top gas outlet connected with heat exchanger inlet pipeline, and bottom liquid outlet connected with feeding opening of rectification tower (B6), which has product outlet connected with first pump (B8), and second heat exchanger (B15) connected with second pump (B14). An INDEPENDENT CLAIM is included for separation of ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas using absorption and hydration coupling device.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram of absorption and hydration coupling device.    Supercharger exhaust pipe (B1)    First heat exchanger (B2)    Heat balance tank (B3)    Absorption tower (B4)    Desorption tower (B5)    Rectification tower (B6)    First pump (B8)    Hydration reactor (B12)    Hydration decomposition tank (B13)    Second pump (B14)    Second heat exchanger (B15)