Method for treating a cracked stream stemming from a fluid catalytic cracker unit (FCCU) comprising the following steps: - compressing and partly condensing the gas stream from the main fractionator column overhead receiver of the FCCU; - separating the partly condensed gas stream in order to recover an upstream liquid and an upstream gas; - heating the upstream liquid; - introducing this heated liquid into an upstream stripper for recovering at the top of the stripper a stream rich in C2 compounds and at the bottom a first liquid stream rich in C3+ hydrocarbons; - introducing the first liquid stream rich in C3+ into a first heat exchanger and then into a second heat exchanger; - introducing the liquid recovered from the second heat exchanger into a stabilizer column for recovering at the top of the stabilizer column a stream rich in C3 and C4 hydrocarbons and from the side of the stabilizer column a liquid stream rich in C5 and C6 hydrocarbons and from the bottom of the stabilizer column a liquid stream rich in C5, C6 and C7+ hydrocarbons; - introducing the liquid stream rich in C5 and C6 hydrocarbons into the first heat exchanger; - introducing a liquid stream from stabilizer column bottom into a primary absorber and introducing the upstream gas into a primary absorber for recovering at the top of the primary absorber a first gas stream; and at the bottom of the primary absorber a second liquid stream; - introducing lean oil from FCCU main fractionator into a sponge absorber; - cooling the first gas stream from primary absorber and introducing it into a propylene absorber; - cooling the liquid stream rich in C5 and C6 hydrocarbons from the first heat exchanger; - introducing the liquid stream rich in C5 and C6 hydrocarbons recovered from the first heat exchanger into the propylene absorber; - recovering a bottom liquid rich in C3 hydrocarbons at the bottom of the propylene absorber and a top gas poor in C3 hydrocarbons at the top of the propylene absorber; - introducing the top gas recovered at the top of the propylene absorber into the sponge absorber, preferably to recover a fuel gas and a rich oil. - compressing and partly condensing the gas stream from the main fractionator column overhead receiver of the FCCU; - separating the partly condensed gas stream in order to recover an upstream liquid and an upstream gas; - heating the upstream liquid; - introducing this heated liquid into an upstream stripper for recovering at the top of the stripper a stream rich in C2 compounds and at the bottom a first liquid stream rich in C3+ hydrocarbons; - introducing the first liquid stream rich in C3+ into a first heat exchanger and then into a second heat exchanger; - introducing the liquid recovered from the second heat exchanger into a stabilizer column for recovering at the top of the stabilizer column a stream rich in C3 and C4 hydrocarbons and from the side of the stabilizer column a liquid stream rich in C5 and C6 hydrocarbons and from the bottom of the stabilizer column a liquid stream rich in C5, C6 and C7+ hydrocarbons; - introducing the liquid stream rich in C5 and C6 hydrocarbons into the first heat exchanger; - introducing a liquid stream from stabilizer column bottom into a primary absorber and introducing the upstream gas into a primary absorber for recovering at the top of the primary absorber a first gas stream; and at the bottom of the primary absorber a second liquid stream; - introducing lean oil from FCCU main fractionator into a sponge absorber; - cooling the first gas stream from primary absorber and introducing it into a propylene absorber; - cooling the liquid stream rich in C5 and C6 hydrocarbons from the first heat exchanger; - introducing the liquid stream rich in C5 and C6 hydrocarbons recovered from the first heat exchanger into the propylene absorber; - recovering a bottom liquid rich in C3 hydrocarbons at the bottom of the propylene absorber and a top gas poor in C3 hydrocarbons at the top of the propylene absorber; - introducing the top gas recovered at the top of the propylene absorber into the sponge absorber, preferably to recover a fuel gas and a rich oil.