Abstract: A fluidized catalytic conversion method for producing light olefins from hydrocarbons, includes the steps of conducting catalytic conversion of an olefin-rich feedstock in a first reaction zone of a fluidized catalytic conversion reactor, contacting a heavy feedstock with the reaction stream from the first reaction zone in a second reaction zone of the reactor for reaction, separating the effluent from the reactor, and recycling the resulting olefin-rich stream to the first reaction zone for further reaction. The method can improve the utilization rate of petrochemical resources and shows high yield and selectivity of ethylene, propylene and butylene.