Fufang Xialian (FXL) capsule, a traditional Chinese medicine (TCM) formula, has been used for a long time to treat Chronic Atrophic Gastritis, but the pharmacodynamic material basis and mechanism of action are unclear. In this research, ferric-reducing antioxidant power (FRAP) method and DPPH scavenging method were utilized to evaluate the antioxidant activity of FXL in vitro. An ultra high-performance liquid chromatography coupled with Linear Ion Trap Mass Spectrometer (UHPLC-IT-MS) method and an ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) method were utilized to acquire the constituents information of FXL. Mass spectra were acquired in both positive and negative ion modes. As the results, FXL showed a moderate DPPH scavenging activity and ferric-reducing antioxidant power. A total of 73 components were identified or tentatively characterized in FXL, which included alkaloids, flavones, flavone glycosides, ginsenoside, lignins, triterpene saponins, flavanones, chalcones and coumarin. The results in this research could provide a basis for further study in bioactivity and metabolites.