AbstractFunctional dyspepsia (FD) is a common digestive disease. Jianwei Xiaoshi (JWXS) tablet is composed of Radix Pseudostellariae (TZS), Pericarpium Citri Reticulatae (CP), Rhizoma Dioscoreae (SY), fired Hordei Fructus Germinatus (CMY) and Crataegi Fructus (SZ). It is a commonly used drug in the treatment of FD in China and has good therapeutic effects. However, there is very little research about the substance basis and action mechanism of JWXS tablet. In this research, ultra‐high‐performance liquid chromatography‐mass spectrometry (UPLC‐MS) and network pharmacology were used to explore the substance basis and action mechanism of the JWXS tablet. Finally, 19, 79, 22, 22 and 39 constituents were identified in the extracts of TZS, CP, SY, CMY and SZ, respectively. Based on these findings, a total of 104 ingredients were identified in JWXS tablet and 29 potentially absorbed ingredients were detected in rat plasma. The results of network pharmacology indicated that the inhibition of gastric acid secretion, the regulation of gastrointestinal motility, inflammation and immune response were the key approaches for treating FD with JWXS tablet. The material basis and potential action mechanism of JWXS tablet in treating FD were comprehensively clarified for the first time. This study will improve our understanding of JWXS tablet.