Method for producing dimethylnaphthalene by fluidized bed reactor

The invention relates to a method for producing dimethylnaphthalene by a fluidized bed reactor, which comprises the following steps: S1, mixing hydrocarbon oil rich in naphthalene series with a methylating agent, introducing the mixture into a turbulent fluidized bed reactor to be in contact with a catalyst, and carrying out methylation reaction in the presence of a fluidizing medium, carrying out oiling agent separation on the obtained oiling agent to obtain a spent catalyst and methylated oil; s2, performing product separation on the methylated oil to obtain reaction gas, naphthalene-containing aromatic hydrocarbon oil and circulating oil containing non-aromatic hydrocarbon and/or naphthalene and methylnaphthalene fractions; s3, performing desulfurization and denitrification on the naphthalene-containing aromatic hydrocarbon oil, and performing aromatic hydrocarbon extraction through an extraction unit to obtain an aromatic hydrocarbon mixture; carrying out aromatic hydrocarbon separation on the aromatic hy