Method for producing low-carbon olefins and various aromatic hydrocarbons from petroleum hydrocarbons

The invention provides a method for producing low-carbon olefin and aromatic hydrocarbons. The method comprises the following steps: (1) feeding heavy petroleum hydrocarbon into a first riser reactor for catalytic cracking; (2) feeding light petroleum hydrocarbon containing the FCC light cycle oil fraction into a second riser reactor, and carrying out hydrocatalytic cracking; (3) carrying out first oil-agent separation on the material led out from the first riser reactor to obtain a first oil-gas product and a first spent catalyst; (4) carrying out second oil-agent separation on the material led out from the second riser reactor to obtain a second oil-gas product and a second spent catalyst; (5) combining the first spent catalyst and the second spent catalyst, and regenerating; and (6) combining the first oil-gas product and the second oil-gas product, and carrying out rectification separation, gas separation and aromatic hydrocarbon extraction separation. According to the technical scheme, the yield of low-c