Abstract: Rhubarb is a Chinese medicinal herb of multiple origins, there are differences in the purgative efficacy of three origins of rhubarb, and the active components of the purgative efficacy of rhubarb is not yet clear. The study reveals the differences in the purgative efficacy of three origins of rhubarb by method of pseudo-targeted metabolomics combined with pharmacological experiments (approval number: BUCM-4-2022080301-3026), and screens out the active components of the purgative efficacy of rhubarb. Analyzing the differences in the purgative efficacy of three origins of rhubarb through animal pharmacological experiments. Subsequently, potential active components of purgative efficacy were identified through literature review, and corresponding ion pairs were obtained by fragmentation pathways and software optimization, and the peak areas of each component were obtained by using dyMRM mode of QQQ-MS. Multivariate statistical analysis was used to analyze the potential active components of purgative efficacy in rhubarb with different origins, thereby achieving pseudo-targeted metabolomics analysis, and the active components can be screened with pharmacological experimental results. The pharmacological experimental results indicate that the purgative efficacy of Rheum tanguticum Maxim. ex Regel is significantly higher than that of Rheum palmatum L. and Rheum officinale Baill. The results of PCA showed that there were significant differences in the potential active components of purgative efficacy among three origins of rhubarb. 97 differential potential active components of purgative efficacy were screened through OPLS-DA combined with Kruskal Wallis test; combined with the results of metabolomics, 23 active components of purgative efficacy were screened, among which the compounds with clear chemical structures were sennoside A, sennoside B, rheinosides A, rheinosides C, rheinosides D, physcion-8-O-glucoside, rhein-8-O-glucoside, chrysophanol-1-O-glucoside. The above results suggest that the method of pseudo-targeted metabolomics combined with pharmacological experiments has been used to clarify the relationship of purgative efficacy between the three origins of rhubarb, reveal the distribution of potential active components of purgative efficacy in three origins of rhubarb, and screen out the active components of purgative efficacy. This not only provides a theoretical basis for the quality evaluation and precise clinical use of rhubarb, but also provides a new idea for traditional Chinese medicine to search for efficacy markers.