Drug dust in pharmaceutical workshops has become a new source of pollution, and it has great harm to the health of employees. Glimepiride, one of the diabetes drugs, is selected as the research object. The terahertz time-domain spectroscopy(THz-TDS) is used to measure the absorption coefficient of its pure product tablet. It can be seen that there are many obvious characteristic absorption peak for this drug in the frequency band from 0.1 THz to 2 THz. The glimepiride tablets is used to generate aerosols to simulate the workshop environment. In order to reduce the influence of water vapor, it is dried by microfiltration membrane and Nafion membrane drying tube respectively. The result shows that compared with the absorption spectrum of the pure tablet, most of fingerprint peaks of the analytes can be identified by both methods. This result provides a good experimental reference for the drug dust detection in the pharmaceutical workshop.