The invention relates to a fluidized bed method for arene methylation and mainly solves problems of large temperature rise of a reaction bed layer, weak stability of a catalyst, several side reactions of an alkylation reagent and low utilization rate of a prior art. According to the invention, mixed feeding of part of dimethyl ether and arene is employed; and remaining dimethyl ether feeding, in form of one stream or a plurality of streams, is introduced into a reactor from one or a plurality of positions at a downstream of a fluidized bed reactor inlet. The above technical scheme well solves the problems and can be applied to industrial production of preparation of paraxylene through an arene methylation reaction.