A fluidized bed reactor for producing para-xylene and co-producing light olefins from benzene and methanol and/or dimethyl ether, including a first distributor and a second distributor. The first distributor is located at the bottom of the fluidized bed, and the second distributor is located at the downstream of the first distributor along a gas flow direction. Also, a method for producing para-xylene and co-producing light olefins, including the following steps: a material stream A enters a reaction zone of the fluidized bed reactor from the first gas distributor; a material stream B enters the reaction zone of the fluidized bed reactor from the second gas distributor; a reactant contacts a catalyst in the reaction zone to generate a gas phase stream comprising para-xylene and light olefins.