The invention relates to a method for preparing propylene and
aromatic hydrocarbon by virtue of conversion of
methanol, and the method is mainly used for solving the problem that the
methanol is just converted into propylene and the
aromatic hydrocarbon can not be co-produced in the prior art. The method comprises the following steps: 1) converting above 80% of
methanol into
dimethyl ether by virtue of pre-reaction; 2) feeding the generated diamethyl
ether and residual methanol into a device for producing propylene from the methanol for reaction so as to obtain a
material flow I which mainly comprises the propylene,
ethylene and C4, C5, C6 and over-C6 hydrocarbons; 3) after the
material flow I is separated, returning the
ethylene back to the device for producing the propylene from the methanol for
cycling reaction, and feeding C4 and C5 hydrocarbons into an aromatizing device for reaction so as to obtain a
material flow II containing
aromatic hydrocarbon; and 4) cooling the material flow II, separating a gas-phase product low-carbon hydrocarbons from a liquid-phase product, and separating the
liquid product from the material flow I so as to obtain C6 and over-C6 hydrocarbons, mixing, extracting and separating so as to obtain the aromatic
hydrocarbon and non-aromatic
hydrocarbon. By using the technical scheme, the problem is well solved; and the method can be used in industrialproduction for preparing the
ethylene and the aromatic
hydrocarbon by virtue of conversion of methanol.