Disclosed are a fluidized bed gas distributor and a fluidized bed reactor, the fluidized bed reactor comprising a first distributor (1) and a second distributor (2), wherein the first distributor (1) is located at the bottom of a fluidized bed, and second distributor (2) is located downstream of a gas from the first distributor (1). Also disclosed is a method for producing a para-xylene and co-producing light olefins, the method comprising the following steps: material stream A enters a reaction zone (3) of a fluidized bed reactor from a first gas distributor (1); material stream B enters the reaction zone (3) of the fluidized bed reactor from a second gas distributor (2); and the reactants are brought into contact with a catalyst in the reaction zone (3) to generate a gas phase stream comprising para-xylene and light olefins.