A method for preparing light
fuel oil and propylene from poor-quality raw oil comprises the following steps: the poor-quality raw oil sequentially enters a first
reaction zone and a second
reaction zone of a catalytic conversion reactor so as to be contacted with a catalytic conversion catalyst to generate first reaction and second reaction respectively, and after gas-
solid separation is implemented to reaction products and spent catalyst, the spent catalyst returns to the reactor for recycling after steam stripping and burning; the reaction products are separated to obtain propylene,
gasoline, heavy oil and other products, wherein the heavy oil is contacted with
hydrogen and a hydrotreating catalyst for reaction, the obtained hydrogenated heavy oil circulates to the first
reaction zone of the catalytic conversion reactor or / and other catalytic conversion devices for further reaction to obtain the target products of the propylene and the
gasoline. The characteristic of the heavy oil obtained by hydrotreating after the mild catalytic conversion of the poor-quality raw oil is significantly improved, thereby significantly increasing light oil, reducing
dry gas, reducing the yield of oil
slurry and realizing the high-efficient utilization of
petroleum resources.