Catalytic pyrolysis of biomass over HZSM-5 can produce aromatic hydrocarbons, but it also produces a lot of by-products and causes rapid coking of the catalyst. Mo/HZSM-5 was modified through ultrasonic treatment to enhance the catalytic efficiency and mitigate the coking in this study. It is found that ultrasonic treatment is conducive to the diffusion of more Mo species into the channel of HZSM-5 and enhance the interaction between molybdenum species and HZSM-5 acid sites, which promoted the synergistic catalysis of Mo species and HZSM-5 and increased the yield of aromatic hydrocarbons. The activity of the ultrasonic Mo modified catalyst increased 54%, which led to aromatic carbon production increasing from 5.09 mmol∙g_cat⁻¹ to 7.82 mmol∙g_cat⁻¹. By adjusting the WHSV, the carbon yield of aromatic can reach 21.7%. The regeneration performance of Ul-Mo/HZSM-5 is excellent, and the activity does not decrease after regenerating seven times.