Disclosed is a method for preparing aromatic hydrocarbons by hydrocracking a polymer containing aromatic rings, which includes reacting the polymer fragment with hydrogen under the action of a catalyst at a temperature of no more than 350° C.; separating a reaction product to obtain the aromatic hydrocarbons. The catalyst comprises a carrier and an active ingredient supported on the carrier, the active ingredient is at least one selected from Ru, Rh, Pt, Pd, Fe, Ni, Cu and Co, the carrier is at least one selected from metal oxide, phosphate, molecular sieve, SiO2 and sulfonated carbon, the metal oxide is at least one selected from Al2O3, Nb2O5, Nb2O5—Al2O3, Nb2O5—SiO2, TiO2, ZrO2, CeO2 and MoO3; the phosphate is at least one selected from NbOPO4 and ZrOPO4; and the molecule sieve is at least one selected from Nb-SBA-15, Nafion, H-ZSM-5, H-Beta and H-Y.