Coal tar pitch (CTP) was modified with cross-linking agent 1, 4-benzenedimethanol over the catalysis p-toluenesulfonic acid in cyclohexane solvent to reduce toxic PAHs content.The effects of modifier addition amount, catalyst amount, reaction temperature and reaction time on the reduction rate of 16 toxic PAHs monitored by EPA were investigated.The optimum conditions were as follows:6%amount of modifier-to-CTP, 12%amount of catalyst-to-CTP, reaction temperature of 50℃and reaction time of 2 h.Under the optimized conditions, the reduction rate of the 16 toxic PAHs in CTP achieved 74.14%.Among them the content of strongly carcinogenic benzo[a]pyrene decreased by 78.38%.The detoxification mechanism was investigated by the reaction between model compound pyrene and 1, 4-benzenedimethanol and via TG-DTG and FT-IR analyses.It was proved that the cross-linking reaction by electrophilic substitution may take place between PAHs and 1, 4-benzenedimethanol.