NOVELTY - Separating method of low-carbon olefin, which uses progressive separation process in traditional ethylene industry, comprises using ethane and/or propane as absorbing solvent in methane removing tower to improve ethylene yield, separating light component from tower top, and separating C2 and components heavier than C2 from the bottom of the methane removing tower; putting the C2+ components into an ethane removing tower; and feeding all C2 components into an ethylene tower, or directly circulating partial C2 back into a reaction system for preparing propylene.    USE - Separating method of low-carbon olefin.    ADVANTAGE - The method avoids using deep-cooling refrigerating case and ethylene compressor and reduces investment and energy consumption.    DETAILED DESCRIPTION - Separating method of low-carbon olefin, which uses progressive separation process in traditional ethylene industry, comprises:    (A) after a series of pre-processing steps of mixing the product of reactor preparing low-carbon olefin from oxygen containing compound or the product obtained in the preparation of low-carbon olefin in catalytic reaction, quenching, compressing, purifying and cooling, separating into gas phase hydrocarbon and liquid phase hydrocarbon through a methane removing tower;    (B) using ethane and/or propane as absorbing solvent in the methane removing tower to improve ethylene yield, separating light component from the tower top, in which the light component contains methane (CH4), carbon monoxide (CO), hydrogen (H2), nitrogen (N2), recovering cold component in the light component to be used as fuel gas or used to produce hydrogen, and separating C2 and components heavier than C2 from the bottom of the methane removing tower;    (C) putting the C2+ components separated from the bottom of the methane removing tower into an ethane removing tower to separate C2 and C3+;    (D) feeding all C2 components separated from the top of the ethane removing tower or the part without ethyne into an ethylene tower, or directly circulating partial C2 back into a reaction system for preparing propylene, improving the selectivity of propylene and feeding C3+ at the bottom of the ethane removing tower into a propane removing tower;    (E) extracting refined ethylene from the top or the upper side line of the ethylene tower, extracting crude ethylene at the lower side line of the ethylene tower, or extracting all crude ethylene from the top of the ethylene tower, or completely extracting the refined ethylene without extracting the crude ethylene; reducing pressure of the crude ethylene through an expanding machine for recovering energy, or reducing pressure and throttling, then recovering the low-temperature cold component, circulating the crude ethylene after reducing pressure and recovering cold component back into the reaction system for preparing propylene to improve the selectivity of the propylene; feeding the ethane at the bottom of the tower into the methane removing tower as the absorbing agent after completely or partially cooling; and    (F) hydrogenizing at the top of the propane removing tower or directly feeding to the propane removing tower, extracting propylene from the top or the side line of the propylene tower, outputting all the propane at the bottom of tower as the by-product or completely or partially cooling to feed into the methane removing tower as the other group of absorbing agent; directly feeding the C4+ component at the bottom of the propane removing tower or feeding into the reaction system for preparing propylene after post processing, or directly outputting as the by-product after processing.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram illustrating an apparatus for separating low-carbon olefin (Drawing includes non-English language text).