Catalytic conversion method and system for producing low-carbon olefins and light aromatic hydrocarbons from crude oil

The invention provides a catalytic conversion method for producing low-carbon olefins and light aromatic hydrocarbons from crude oil, which comprises the following steps: S1, carrying out flash evaporation on the crude oil to obtain light distillate oil and heavy distillate oil; contacting the light distillate oil with a first catalyst in a downer reactor to obtain a first semi-regenerant; s2, respectively introducing a second catalyst and the first semi-regenerant into a riser reactor from the bottom and the middle part; introducing the heavy distillate oil into the riser reactor from the bottom, and sequentially contacting the heavy distillate oil with the second catalyst and the first semi-regenerant for a second catalytic conversion reaction to obtain a second oil agent mixture; s3, the second oil agent mixture is guided into a catalyst separation device to be separated; and S4, carrying out gas-solid separation on the third oil agent mixture. The invention also provides a catalytic conversion system. Acc