In this paper, a rapid detection method for estazolam based on terahertz spectroscopy technology is developed to solve the problems of cumbersome pre-processing, sample loss, long time and high cost in the detection process by HPLC. Firstly, DFT is used to predict the molecular vibration mode of estazolam in 0.9-20.0 THz frequency band, and a qualitative analysis method is established. Secondly, by analyzing the correlation between the content of estazolam and the characteristic peak of terahertz, a quantitative analysis model with a high fitting degree is established. Then, the terahertz spectrum analysis of 22 estazolam products from different manufacturers is performed, and the SVR algorithm is combined to achieve an accurate quantification with MAE of 1.12% compared with the HPLC method. The method has the advantages of simple operation, fast analysis speed, low cost and non-destructive testing, which provides a new analytical strategy for the quality control of special drugs, and has the potential to be extended to the quality evaluation of other anesthetic drugs.