Artemisinin and its derivatives: dihydroartemisinin, artemether, artesunate, are a group of sesquiterpene lactone with a 1, 2, 4-trioxane ring system and possess a rapid action against malaria. Due to its pharmacological features such as efficiency, low toxicity, low cost, safety and so on, they have become one of the most widely used antimalarial drugs. However, there are still some ambiguity in the current terahertz fingerprint spectrum data, which is difficult for the rapid and nondestructive identification of these drugs. In order to further improve the terahertz fingerprint data of artemisinin and its derivatives, here, the terahertz time-domain spectroscopy (THz TDS) was used to measure the THz spectra of artemisinin, dihydro artemisinin, artesunate and artemether, and the characteristic absorption spectra were obtained in the range of 0.2 to 2.7 THz. Compared with the experimental results and the previous reported data, our experimental data showed that most of the resonance peaks were consistent with the literature [3], but the peak position and intensity were slightly different, and some new peaks were observed. Furthermore, the influence of sample preparation, data processing method on the results and the relationship between molecular structure and peak position were discussed, and the validity of the data was confirmed. This study provides a reference for the further study on the properties of artemisinin and its derivatives, and provides a rapid and effective method for the identification and quantitative analysis of artemisinin and its derivatives.