A process for increasing the production of a light olefin hydrocarbon compound from a hydrocarbon feedstock, comprising the following steps: (a) feeding a hydrocarbon feedstock into a pyrolysis furnace to conduct a pyrolysis reaction; (b) separating the pyrolysis reaction products, into a stream containing hydrogen and C4 or lower hydrocarbons and a stream containing C5+ hydrocarbons, through a compression and fractionation process; (c) recovering hydrogen and C2, C3 and C4 olefin and paraffin hydrocarbons, respectively, from the stream containing hydrogen and C4 or lower hydrocarbons; (d) separating pyrolysis gasolines and a C9+ hydrocarbon-containing fraction from the stream containing C5+ hydrocarbons, using hydrogenation and separation processes; (e) feeding the separated pyrolysis gasolines, a hydrocarbon feedstock and hydrogen into at least one reaction area; (f) converting the hydrocarbon feedstock in the presence of a catalyst in the reaction area into (i) an aromatic hydrocarbon compound which is rich in benzene, toluene, and xylene through dealkylation/transalkylation reactions, and into (ii) a non-aromatic hydrocarbon compound which is rich in liquefied petroleum gas through a hydrocracking reaction; (g) separating the reaction products of step (f) into an overhead stream, which contains hydrogen, methane, ethane and liquefied petroleum gas, and a bottom stream, which contains aromatic hydrocarbon compounds, a small amount of hydrogen and non-aromatic hydrocarbon compounds, using a gas-liquid separation process; (h) circulating the overhead stream into the compression and fractionation process of step (b), wherein a portion of the overhead stream is separated and then recycled into the reaction area of step (f), or the entire overhead stream is recycled into the compression and fractionation process of step (b); and (i) recovering the aromatic hydrocarbon compounds from the bottom stream, wherein the process further comprises circulating at least a portion of the recovered C2-C4 paraffin hydrocarbons which are respectively recovered in step c) into the pyrolysis furnace of step (a). (a) feeding a hydrocarbon feedstock into a pyrolysis furnace to conduct a pyrolysis reaction; (b) separating the pyrolysis reaction products, into a stream containing hydrogen and C4 or lower hydrocarbons and a stream containing C5+ hydrocarbons, through a compression and fractionation process; (c) recovering hydrogen and C2, C3 and C4 olefin and paraffin hydrocarbons, respectively, from the stream containing hydrogen and C4 or lower hydrocarbons; (d) separating pyrolysis gasolines and a C9+ hydrocarbon-containing fraction from the stream containing C5+ hydrocarbons, using hydrogenation and separation processes; (e) feeding the separated pyrolysis gasolines, a hydrocarbon feedstock and hydrogen into at least one reaction area; (f) converting the hydrocarbon feedstock in the presence of a catalyst in the reaction area into (i) an aromatic hydrocarbon compound which is rich in benzene, toluene, and xylene through dealkylation/transalkylation reactions, and into (ii) a non-aromatic hydrocarbon compound which is rich in liquefied petroleum gas through a hydrocracking reaction; (g) separating the reaction products of step (f) into an overhead stream, which contains hydrogen, methane, ethane and liquefied petroleum gas, and a bottom stream, which contains aromatic hydrocarbon compounds, a small amount of hydrogen and non-aromatic hydrocarbon compounds, using a gas-liquid separation process; (h) circulating the overhead stream into the compression and fractionation process of step (b), wherein a portion of the overhead stream is separated and then recycled into the reaction area of step (f), or the entire overhead stream is recycled into the compression and fractionation process of step (b); and (i) recovering the aromatic hydrocarbon compounds from the bottom stream, wherein the process further comprises circulating at least a portion of the recovered C2-C4 paraffin hydrocarbons which are respectively recovered in step c) into the pyrolysis furnace of step (a).